Let me say: Axis&Allies is one of the most unrealistic wargame I ever saw. When, 10 years ago, tried briefly it, it looked like an evolved RisiKo.
Most of the top producers of serious wargames are missing at the moment (I'm talking about Avalon Hill, International Team, for example).
You can still find Australian Design Group that created one of the most complete and complex strategic simulation: World in Flames (with Days of Decision starting by 1936).
This is a serious game, complex, with a plenty of options (strategic, military, production, diplomacy - if more than 2 players), but be warned: it's very hard to know... but granted we are talking in BG boards... I do not think it's a problem.
Regards.