2-player war game I would heavily recommend is Memoir '44.
I adore the fantasy version Battelore and when I got to demo it to a few rpsers at our social meet up they all had good things to say about it (Rab may cover Battles of Westeros soon which is the updated version of Battlelore -sort of, as it different rules etc)
Memoir '44 uses the same mechanics, but in WWII. You have tanks, infantry and artillery. It may look overwhelming when set up, but your orders are limited by cards and you only have a few cards in your hand which say things like ‘activate 3 units on your left flank’.
Games play under an hour, so play a scenario. Then flip it around and play the opposing -or get a game in with each.
As much as I loath suggesting giving Risk any more money there are more variants of Risk out there if you can bear playing them. Risk Tactics is, I think, the latest version out which is supposed to offer more strategy and quicker play.
When it comes down to it, games are great if played with the right people, so if you are lucky enough to have a group then anything works.