I must admit, I went a little overboard this year. Last year was my first year playing fantasy baseball and I just stuck with MLB. This year, I'm doing Yahoo (as a player in one league and a commissioner in another league), ESPN, CBS and MLB. My Yahoo teams are doing the worst, but I think it's the friendliest site. ESPN is doing the best, but would say that's second. My CBS team hasn't been drafted yet and am wondering if it ever will. So that's a bit of a problem, just waiting to get the league full before drafting. MLB is easy and good for beginners as you have less to worry about.
Just my two cents.