These benefits are in no particular order, although first one listed is the number 1 reason a baby should be breastfed.

Breastfed Babies Receive the BEST Nutrition
This can not be mentioned enough, as you will see it often plastered in every breastfeeding book and baby book, breastfeeding is the ideal, the absolute best nutrition for a baby and even that appears to be an understatement, breastfeeding can save your baby's life. Studies show that breastfeeding can potentially save or delay approximately 720 postneonatal deaths in the United States each year. Source Undoubtedly breastfeeding as been proven to be what babies should eat.

Breastfed Babies Receive the Nutrition That Was Designed for Them
Breast milk can not be duplicated, even the so called best of the best artificial baby milks that are manufactured pales in comparison to the food that babies are born to Receive As you are breastfeeding your child you can rest assure that they are getting exactly what their growing bodies need.

Breast Milk Passes Meconium Through a Babies Body
When babies are born they have a tar-like substance in their intestines called meconium. Colostrum, early breast milk, is designed to help move meconium through the infant' body.

Breast Milk Helps With Proper Intestinal Development
Breast milk contains a unique protein that acts as a protective substance, promoting the growth of the cells that line a baby's intestines.

Breast Milk Helps With Proper Development of the Gastrointestinal Tract
When a baby is born their gastrointestinal system is not yet mature. Breast milk helps it mature, and much faster than artificial baby milk.

Breastfeeding Promotes Proper Brain Development
Breast milk contains taurine, an amino acid that is virtually absent in cow's milk, and research shows that it promotes good and proper brain development.

Breastfeeding Promotes Proper Nervous System Development
Breast milk contributes to the proper development of the nervous system, as it does with brain development, lending help to the cognitive development of a breastfed baby. Something that will affect them for the rest of their lives.

Breastfeeding Lowers the Chance of Cardiopulmonary Distress
While a baby is feeding they have less of a chance of cardiopulmonary distress. According to a study babies can experience an oxygen saturation of below 90% when bottle feeding.

Breastfeeding Protects Your Baby Against Hemophilus B. Bacteria
The bacteria Hemophilus Influenzae Type B can be growing in the respiratory tract without any symptoms, and can spread into the throat, ears or blood, causing a serious illness. Babies and children who were breastfed are much less likely to contract Hemophilus B.

Breastfed Babies Have a Shorter Pre and Post Surgical Fasting
Unlike artificial baby milk breast milk can be consumed three hours before a surgery, unless otherwise stated by your doctor, in healthy children having an elective surgery.

Breast Milk Helps the Development of a Healthy and Strong Immune System
Countless studies have proved that breastfeeding leads to a strong and healthy immune system, which means your breastfed baby will forever be less sick than if they had not received breast milk.

Breastfed Babies Are Sick Less and Miss Less School
Since a breastfed baby goes through life less sick they will miss less school.

Breast Milk Changes With Your Baby
As your baby grows your milk changes for their needs, even preterm milk is designed for preterm babies.

Breastfeeding is One of the Few Things You Can Do While Sleeping
Once your baby is latched on you can fall asleep and be breastfeeding as your baby peacefully suckles themselves back to sleep at your side. This is not something that you could say about bottle feeding as it is dangerous to prop a bottle and go to sleep.

Breastfeeding is Super Convenient
You can breastfeed anytime, anywhere and in any condition. This is something that is super convenient for both mommy and baby.

Breastfeeding is Forever, or At Least Until Your Baby Decides to Wean
As long as your baby is regularly and effectively breastfeeding your body will keep making milk.

Breast Milk is a Natural Pain Relief for Your Baby
Breast milk contains endorphins, chemical that suppress pain leading to a happy feeling.

Breast Milk of a Sick Mommy Contains Antibodies to Help Prevent Baby from Getting the Same Sickness
There is no worry about temporarily weaning, something that is not recommended ever, if you are sick. Your breast milk will have antibodies to help prevent your breastfeeding baby from getting sick.

Breastfeeding Gives Baby More Sleep
When all you have to do is latch on, getting back to sleep is easy. If you have to wait for your mom to prepare a bottle you'll become more awake and crankier and in the long run have a harder time falling asleep.

Breast Milk Never Spoils in the Breast and Will Never Be Recalled
Artificial baby milk has an expiration date and can be recalled and has been recalled before.

Breastfeeding Strengthens and Aids to Proper Development of the Jaw
The simple and repeated motions of suckling of a mother's breast strengthens and help properly develop a baby's jaw.

Breastfeeding Lowers the Risks of Tooth Decay
Breast milk has bacteria fighting cells that help kill the bad bacteria that causes tooth decay.

Breastfeeding Your Baby Helps the Environment
Really the only thing that you need to make milk is your breast, something that you are born with and already have without using any resources. Artificial baby milk, formula, uses resources to be made and all of the containers that it is held in, shipping supplies, pamphlets that formula companies send free to mothers that send misleading information, plastic bottles, nipples, etc. amount to a lot of garbage. Plus with all of the sterilizing that you have to do with the nipples and bottles heat and water is wasted.

Breastfeeding is Less Stressful than Drinking Out of a Bottle for Babies
Suckling from the breast is less stressful for a baby, especially a premature baby who can not handle stress well, then sucking milk out of a bottle.

Breastfeeding Optimizes Hand-To-Eye Coordination for Babies
Babies who suckle at the breast are reported as being able to see and manipulate objects quicker.

Breastfeeding Lowers the Risks of Cancers for Baby and Mommy
Babies who are breastfed have a lower chance of developing certain childhood cancers and breastfed baby girls have a lower chance of developing breast cancer. By breastfeeding a mother lowers her chance of developing such cancers as ovarian cancer, cervical cancer, breast cancer and endometrial cancer.

Breastfeeding Lowers the Risks of Diseases for Baby and Mommy
Breast milk contains immunities to many diseases lowering the risk of babies getting them. These diseases include ulcerative colitis, necrotizing enterocolitis, crohn's disease and hodgkins disease. There are studies that show that a breastfeeding mother can lower the risk of getting certain diseases such as endometriosis.

Breastfeeding Lowers the Chances of Getting Certain Infections
Babies who are breastfed have a lower chance of getting such infections as ear infections, diarrheal infections, stomach infections, bacterial meningitis, urinary tract infections, respiratory infections and eye infections. Breastfeeding moms also have less urinary tract infections.

Breastfeeding Lowers the Risks of Health Conditions for Baby and Mommy
There are many health conditions that breastfeeding helps prevent for both baby and mommy. Breastfed babies have a lower risk of SIDS and such health conditions as having allergies all through their life, becoming diabetic, becoming obese, developing asthma, developing high cholesterol, developing high blood pressure, developing rheumatoid arthritis, inguinal hernia, osteoporosis, bad vision, eczema and multiple sclerosis. Breastfeeding lowers the risk of a mother developing osteoporosis too, as well as such other health conditions as anemia.

Breast Milk Taste Perfect to a Baby and Better than Artificial Baby Milk
Since breast milk is what is designed for a baby it taste great to a baby, in fact breast milk is very sweet and warm, unlike artificial baby milk that is bland.

Breastfeeding Aids to Better Speech Development
Oral motor development is strongly influenced when a baby is fed via bottle as opposed to breast. Babies who breastfeed are more likely to have better speech development.

Breastfeeding Helps a Tired Baby Fall Asleep
Breast milk contains chemicals that act as a natural tranquilizer for a baby helping them either calm down or fall asleep if they are tired.

Breastfed Babies Statistically Have Higher IQs
Studies have shown that babies who breastfeed go on to have higher IQs than babies who received artificial baby milk.

Breastfed Babies Have Silky Skin
Breast milk contains fats that not only provide energy but also gives a baby firm flesh and silky skin, something that does not come with artificial baby milk.

Breastfed Babies Spit Up Less
Babies who breastfeed spit up less, this means less laundry to wash as well as less outfit changes of both baby's and mommy's clothes.

Breast milk is the Most Digestible Substance for a Baby
Breast milk is the easiest thing that you can give your baby to digest as it is designed so they can consistently digest it without any complications.

Breastfed Babies Who are Sick Don't Have to Change Their Diet
Breast milk is the perfect food for a sick baby.

Breastfeeding is Best Even in Special Situations
Breastfeeding is better for premature infants than any other substance, regardless that they have a special situation.

Breast Milk Doesn't Contain Any Genetically Engineered Materials
Carnation Alsoy, Similac Neocare, Isomil and Enfamil Prosobee, artificial baby milk manufactures, have all tested positive for genetically engineered materials. Breast milk is free of genetically engineered materials.

Breast Milk Doesn't Contain Any Synthetic Growth Hormones
Synthetic growth hormones are routinely ingested by cows in the United States. Milk based artificial baby milk can contain them too, where as breast milk will be free of synthetic growth hormones.

Breastfed Babies are More Likely to Have Better Social Development
Whether your baby is a shy person in life, or chatty person in their life will be determined by their personality. Breast milk will aid to their ability to handle social situations better as is aids to good social development.

Breastfeeding Allows a Mom to Feed & Comfort Her Baby at the Same Time
Babies are comforted by suckling and so nursing is very comforting to them, so this benefit it beneficial for both mommy and baby.

Breastfeeding is a Way a Baby Can Bond With Mommy
Although breastfeeding is a wonderful way that a baby and mommy can bond, it is not the only way a baby can bond with someone. Holding a baby, playing with them, bathing them, dressing them and changing their diaper are examples of how anyone can bond with the baby.

Breastfeeding Offers Many Unique Benefits for Mommy
There are many benefits that breastfeeding give a mother. Breastfeeding moms get more sleep and can feed their babies in their sleep, have no stress preparing breast milk, as it happens involuntarily, save more money on doctor bills and dentist bills, if they are diabetic breastfeeding decreases insulin requirements, their uterus contract quicker, they lose baby weight faster, because their kids are sick less from being breastfed mom (and dad) take off less work from their kids being sick, also don't have to worry about getting sick from their kids as much and save money on medicine cabinet supplies, they prevent postpartum hemorrhage, delay their menstrual cycle and save money on menstrual supplies, they have an excuse to sit or lay down and relax, they eliminate any cost of fake baby milk and save on taxes, along with the rest of the country, and statistically have better confidence as a mother.

Breastfeeding Doesn't Support Artificial Milk Manufactures Whose First Agenda is Profit and Not the Health of Babies
The less formula that is bought the better.

Breastfeeding Promotes Breastfeeding
When a mother breastfeeds she is promoting breastfeeding.

Breastfeeding Helps Mom Stick to a Healthy Diet
Since a mother breastfeeds her baby for years after pregnancy she not only continues to take her vitamins but she also wants to keep eating healthy meals.

Breastfeeding Helps Hospital Patients
Breast milk is sometimes given to cancer patients under going chemo treatment, burn victims and organ transplant patients.

Breast Milk Can Be Used to Treat Diaper Rash
If you ever find yourself out of diaper cream and your little one get diaper rash breast milk will work as an alternative.

Breast Milk is Great for Mouth Cuts
If your baby bites their tongue or cheek breast milk will help keep the cut from becoming infected.

Breastfeeding Benefits References Include:
The Womanly Art of Breastfeeding, by La Leche League International
Mothering Multiples, by Karen Kerkhoff Gromada
Nursing Mother, Working Mother, by Gale Pryor
LLLI.org
Promom.org 101 Reasons to Breastfeed