I go to UC Berkeley, which is a really difficult school to do well when you have 500-600 hardcore pre-meds in all of your science classes and 60% of the class gets a C or worse. I've had over a year of research experience, I've shadowed a doctor, volunteered at a hospital and I got a 35 on my MCATS. My GPA however, leaves a lot to be desired. I really screwed up my first two years in almost all of my undergraduate science courses (except gen. chem=B+ and Physics 8B=A-), but almost all of the others were C's except a few. During my junior and senior year I "woke up" and got almost all A's and a few B+'s and one A-. My overall GPA is like a 3.1-3.2 right now and I need to do something for a year or so in order for my senior year grades to be counted in my GPA when I apply. Should I work in a lab doing research, take a post-bac program and get A's, or would they be most impressed if I did something like join the Peace Core and volunteer (in a medically-related way) in some third-world country?