http://www.uworld.com
This Qbank is a definite must for anyone serious about scoring for the USMLE. Questions are hard so don't feel discouraged if you are not scoring well initially. Make sure to read all the explanations (even for questions you got correct) as this is where UWorld really shines (has the best explanations of all the Qbanks). Annotate what you do not know in your FA.
The advantage of UWorld is that it really tests your concepts and ability to integrate information from different disciplines. Questions are not straightforward and challenging but it really helps you get the hang of the multi-step question format that USMLE is so famous for.
I recommend doing the bank to stimulate the real exam; which means select
- all subjects and disciplines
- random questions
- timed
Note: There is a mobile version for iPad/iPhone so you can access it on the go.