I haven't read the other responses yet, because yes (!) this can be a very controversial subject, and I want to get my own answer down before reading what everyone else has to say.
First of all, there is a wonderful book called The Vaccine Book by Dr. Sears. It lays out all of the routine childhood vaccines, tells you about the vaccine, its ingredients, the disease(s) it can prevent, etc, so YOU can decide what YOU think about each vaccine and decide if it is for your particular child. The book is SO informative. I believe that no matter which way you go with vaccinating, it is super important to be informed. Blindly vaccinating along with the typical schedule can be just as bad an idea as blindly refusing ALL vaccines out of hand.
For us, personally, I did not feel we needed to vaccinate along with the usual schedule. My son was 100% breastfed (which protects against a LOT of the illnesses we vaccinate for) and he was not in daycare, and did not regularly go to playgroups. I did not feel we were in the high risk group. Also, genetically, my son is at high risk for learning disabilities and other disorders of the brain like depression. I wanted to do everything I could to reduce his exposure to harmful chemicals (everywhere, not just in vaccines) and for us, not vaccinating was one way to reduce his exposure to give him the best chance at having a normal life. (I also do not bring chemical cleansers into our home, I buy natural and organic foods, etc. Vaccines were only one piece of the puzzle.) He breastfed for thirty months, to give his own developing immune system a chance to catch up before being "on its own."
My son has had a few vaccines (less than five) spread out over the past three and a half years. Using The Vaccine Book and other research I decided which would benefit him most with the least chance of causing harm.
That all said, I still believe 100% that we have done right by our son. He is nearing four, and is the healthiest child I've ever met. He has never had rotovirus, pneumonia (or even a serious cough), or anything more than a strong cold. He has had exactly one ear infection (in his whole life!), at the age of 23 months.
So do the research, do the reading, take into account your lifestyle, health and genetics, and decide what is right for your family. A child who weans from the breast at age 8 weeks and goes straight to daycare before taking a tour of Eastern Europe at age one would probably need more protection via vaccines than a child who stays home with M. and nurses to two years and beyond and then goes on to be homeschooled. ...And most of us fall somewhere in between.
But that's just my opinion. ;o)