I took Kaplan and found it to be sufficient. Not awesome, but definitely helpful. For me, the classes were okay, but what I really liked was the Kaplan study center.
They had one nearby, and I was able to spend all day studying in relative peace and quiet (as opposed to the college or public library). They also have tons of old LSATs that you can take and get immediately graded with a breakdown on your strengths and weaknesses. Also, there was always at least one LSAT instructor available as well as the other students, so you could always get feedback.
I know a lot of people don't like Kaplan, but I found it useful. My score went up quite a bit from my diagnostic, which I think was 154. Specifically, I found Kaplan to be helpful with reading comp. I don't think I would have figured out the best approach to that on my own.
Anyway, your mileage may vary.