Another great learning path you can take is 1941, 1942, and finally 1940. More complicated/bigger usually equals more fun and more time-consuming.
Anniversary is still the most popular among loyal but infrequent gamers.
Which one should I buy and what is the difference in the 2? Is Iron Blitz a release to fix bugs and be a better game, or is it just and expansion to include ‘marines’ & ‘destroyers’ etc.?
Appearantly you can’t buy Iron Blitz anymore, but you can still get the original A&A just about anywhere fairly cheap.