Exposure is the key. I recommend going to an institution that provides a broad patient population, preferably in an inner city environment. I did my rotations almost exclusively at Henry Ford Hospital in Detroit, this proved to be an excellent facility both in didactics and case loads.
There are numerous hospitals that fall in to the same category as henry ford. Attempt to find out the type of patient population seen in the hospital. Suburban medicine can be quite different from the amazingly noncompliant population of the inner city. Hope this helps.