I'm gonna have to throw my hat in for Step-Up to Medicine. I essentially used this as my one and only text for medicine (supplemented with my annotated First Aid for Step I for pathophys stuff that was a bit weak), and then used MKSAP and Kaplan Step 2 Qbook for questsion sources. Through the course of my 12 week IM rotation I read through Step-Up twice and was doing MKSAP from the beginning. If I had better study habits, I could've made it through Step-Up for a third time. I didn't use Cecil's or Harrison's or any of that crap. I had a Pocket Medicine in my white coat, but I may have used it all of twice during my rotation.
In the end, I demolished the shelf and I regularly got "outstanding fund of knowledge" on my evals primarily because I was faithful to Step-Up. It's solid gold! I would recommend it to ANYone who's starting IM, regardless of whether you learn better from "review books" or not.