Out of your 4 years in med school, you are required to do like one month of psych. If while in med school you decide you want to pursue psych, you'll probably take a total of 3 months of psych. Again, that's 3 months of psychiatry in all 4 YEARS of your med school career for anyone who goes into psych after med school. It is in residency where you truly learn about your desired specialty. So, this question should be more like, "what are some of the stronger psych residency programs across the nation?"
Pick a med school based on location, cost, and the "vibe" you get from the school and city.
PS. When it's time for residency...guess what...it's mostly about location and vibe once again. That's how you choose.