It also depends on where you're located and who you'll get as your teachers. For me, I really liked Princeton Review, and all my teachers were insanely smart, scoring 36+. The guy who taught orgo scored 15 on BS, so it was obvious he knows what he's talking about, and all of them have taught these courses before. Contact your local office for Kaplan and TPR and see what kinds of instructors they have.
Another reason I liked TPR was their diagnostic tests and online practices. I think their practice material is most similar to the real MCAT.