I would say that any residency program that you train at will give the skills to become a good physician. Having said that, I also feel that by going to a "prestigious" program, you are provided expereinces and opportunities that might not be available to you had you gone to a let's say, a local community hospital program. The presitigious programs are usually affiliated with hospitals that are known for their excellence as a tertiary center. Consequently, if you are at one of these programs you'll be exposed to "fascinomas" that you would only read about in a textbook at another program. Going to a prestigious program will also put you in contact with leading experts in certain fields that may help you when you are looking for a fellowship position. Finding jobs after you graduated from a local community hospital may not be a problem if you are planning on staying in the area, but by going to a prestigious program, you are opening doors across the country. I feel, however, that you should go to a training program that you feel the most comfortable at. There are many personalities out there when you look at training program -- you'll get the most out of a residency if your personality matches that of the residency program. These are just some thoughts. Hope this helps.
-james