One piece of advice that gets mentioned often, not just by me, is to choose the period and theatre that most interest you and you'll be guaranteed to enjoy. Personally for WW2 I like BN and FB, however, FI with it's 2 modules and RT with the FR module offer lots of content too. For modern I like CW hands down. Great content, but partly it's because of 10 years as an Army officer in that era so it's what I trained for for years. Interesting to play it out. Although while in the 82d our mission was a bit different than armored combat in the Fulda Gap, and many times we were occupied with [waves hands] "other things"
Dave