I've been to many different language classes. From Welsh and French in school, to Catalan in university and German and Spanish at language institutes. Some of those classes have been excellent (Catalan in Manchester, thank you Àdria), some less so, which brings me to a question: Should I go to class anymore? This is a common discussion over at HTLAL, with most people plumping for the study-alone option - which is probably more related to the people taking part in the discussions over there than any general consensus in the matter. My personal conclusions are as follows:

1) Language classes can work if they are used for specific purposes by motivated students who use them as part of a wider learning strategy
2) Self-study is a great option for those with strong willpower, and if you already know what works for you in language-learning
3) I'm going to go to less language classes, and concentrate more on reading books and watching TV as well as active production

I'm not against language classes, even though my Catalan class goes slowly I like how I can use it as a central pole from which to base my outside learning and gauge my progress, but as I think about starting my 5th language (Swedish this summer) I think I'm going to base more and more of my learning on my own back.