The best recommendation I can give out is to try to sit in on a class to see if you like how the instructor teaches. It seems that every school probably has good and not-so-good instructors. The dynamics of the class can make a difference as well. It was good for me to be in a class where the only language we could talk to each other in was German.

I was able to sit in on a class at Klubschule Migros before I committed to an entire course and found that the instructor was excellent. One thing the instructor did that I found great for learning was to take a break for coffee in the middle of the the (3 hour) class, where we would all just simply chat with each other in German.