First, I think you should try to schedule one ob/gyn rotation, either general or one of the specialties. This should be an away rotation at a program that you want to check out, unless you are dead set on your home institution. This will give you a little more prespective about differences in residency programs, you will be able to showcase yourself to them, and maybe get an LOR.
As for other rotations I would suggest:
ICU (either MICU or SICU) will give you invaluable knowledge regarding fluid mgmt, tx of infections/sepsis, cardiovascular drugs, pulm/vent mgmt, experience at least watching codes, etc. etc. And if you play nice the residents usually let you get some procedures, lines, chest tubes, and the like.
EM gives you great exposure to anything and everything and will definately teach you to make great differentials and think of everthing possible. Also, the hours are ever so cush, I mean who can argue with working 17 shifts over a rotation that lasted 27 days!
A medicine subspecialty, I am doing Cardiology because heart problems and their drugs are so common I wanted to increase my knowledge. Also, I wanted to get improve my EKG interpretations skills. The other medical subs I would suggest are Renal so you won't have to ask "what does this BMP mean?" and endocrine because everybody and their momma's got diabetes.
Other ones might include Derm b/c people are always gonna ask you about a bump or a rash ( but when you're on your derm rotation NEVER say rash!) Also outpt medicine or family would be beneficial.