As Petina points out, we`re all different. I would avoid the `one-size-fits-all` classes, books etc. Try to model a self-learning programme around your own learning style. Don`t worry about getting bogged down in heavy grammar and text books. There are plenty resources and learning communities on the web, so you don`t have to spend a penny. Spend time watching/listening to stuff you enjoy, such as music, anime, comedy. If you make it enjoyable it`s much easier.

Me? I live in Japan now and spent many years paying for classes and textbooks, but realised it`s in their interests to keep you as a student. Now I do a few hours core study per week, but the real development comes from just watching my favourite TV shows, listening to music, radio and going down to the local Izakaya on Friday to chat with people.

Don`t worry too much about grammer. It comes naturally after you get the basics.