I am using Step-Up to Medicine, Recall, and MKSAP for IM. Both Step-Up and MKSAP were suggested to me. Recall was my own selection.
Pocket Medicine, Scut Monkey (Clinician's Pocket Reference), and the Washington Manual (haven't purchased yet) were also suggested to me to carry (have on hand). Scut looks to be very good. Oh, and Epocrates to help during the daily chores on the wards.
Otherwise, the other general reading I plan to do is "Pocket" Harrison's (on my PDA). Who has time for BIG Harrison's? Notice a trend? BIG Robbin's, BIG Harrison's? LOL! Pocket Robbin's (when I read it) was good enough, imo. Hopefully Harrison's pans out to be the same.
For Surgery, I have heard Recall is the thing to hit.
For Psychiatry, FIRST AID. Our M2 Psychiatry course used it and I like it.
For the others, I have not decided yet. I'd ask your upper class persons. They are going to be the experts at your school.