Listed are some great books for Step prep as well as for their respective class.

All books listed are in Excellent Condition unless noted otherwise.

Essential for Step Prep:

HY Behavioral Science (3rd ed) - $10
BRS Physiology (4th ed) - $20
Rapid Review Goljan Biochemistry (2nd ed) - $10

Also good for Step Prep:

HY Neuroanatomy (4th ed) - $10
HY Gross Anatomy (3rd ed) - $10
HY Cell and Mol Bio (2nd ed) - $10
FA 2009 - $10, (This is great for those that won't take the Step until the 2011 version comes out, so you can annotate into the book while in your classes.)
FA Cases for USMLE Step 1 - $10
Rapid Review Micro/Immuno - $10

The best books for their class:

Costanzo Physiology (3rd ed) - $20
Lippincotts Biochemistry (4th ed) - $20, Good condition
BRS Anatomy (6th ed) - $10