Out of the review books out there, Medstudy is good. The DVDs are lectures, while good, are boring to me, I've barely made it through 1 section here at my residency. If you want Medstudy, you'll probably want the Core curricula series, which is a condensed study guide basically.
I've used Mayo's, Cleveland Clinics, first aid for IM Boards, as well as Medstudy, and Medstudy is probably the best, but the other 3 are substancially cheaper and are also very good themselves. First aid is almost identical to the lay out of the Step 1 version, Mayo's is similar but a little wordier, and the Clinics is well, a wordier version of First aid as well.
If you want a question bank or review questions, you'd probably be better served with the MKSAP questions.
