best OB residencies?

REI is not that competitive. Gyn onc is ridiculously competitive. If you are even remotely interested in onc you should avoid most community programs (Carolinas Medical Center in Charlotte is an exception I can think of) and go to the strongest academic program you can and one step better is to go to a program that already has an onc fellowship. The US News rankings are just a guide. They certainly don't tell the whole story. Take Hopkins for instance. It is ranked number 1 in US News and has been for several years but their ob/gyn residency has been on probation several times in the last few years for various reasons. Another example, Duke's hospital is ranked above UNC in US News but UNC has the better reputation as far as residency training goes. The best thing to do is to talk to someone in the ob/gyn dept at your school who is knowledgable about this stuff.