Good question. I wanna know, too.
I used 5 Steps to a 5 for Calculus AB. It helped a lot (if you actually read through entirely and do the practice questions.) The practice tests suck though. They're unrealistically easy. And the book doesn't cover a few things like Intermediate Value Theorem.
I've heard about Barron's, but then again I've also heard it covers too much unnecessary stuff and the practice tests are unrealistically difficult.
So now I have no idea what to use.
I personally find math to be one of the subjects where prep books aren't entirely helpful. If I ever get stuck on a topic, I ask a teacher or use Khan Academy, because you can't really cram too much with math. I usually only use prep books for the practice tests, so I purhased the Princeton Review. Normally not a huge fan of PR, more of a Barron's guy myself, but usually PR has practice questions most similar to the real deal.
I agree with Rob1995. I would just stick with whatever calculus textbook you're using; they usually cover the same or similar topics on the BC test. I'd only use a prep book if I want to take a practice test or something.
I thought Princeton Review was the best to teach me calculus last year, far better than my calculus book. Its material was a little bit more simple than the real AP test though. I also went to Barron's after PR and found that it was way harder than the real test.
