rotation picks

Best:
Surgery -- *loved* the rotation, but hated the lifestyle
Medicine -- tons of teaching, you get to think through problems, and students are treated like they're "part of the team."
CCU (Coronary care unit) -- by far my all-time favorite rotation. Perfect mix (for me) of evidence-based medicine, procedures, thinking through problems. The patients usually feel better when they're discharged!
Pulmonary -- the most interesting patients I've had have been while I've been on this rotation -- they're also the sickest. Also a fair amount of procedures, and really friendly attendings who are into teaching (at least here...) It's a great rotation whether or not you're interested in IM.

Worst:
Peds (especially outpatient) -- I hate constantly having to reassure parents who are overly worried about their perfectly healthy children! The really sick children are just too depressing, and I would probably burn out by the time I'm 35.
Ob/Gyn -- Some of the most unhappy and unfriendly physicians I have met so far.