Over the years, I've played a lot of Battlecry and Memoir 44. I have a gamer co-worker and the campaigns for these games are broken up into battles that are easily played in an hour... or, at least, not TO much longer than an hour. Note: In over 3 years of lunch time game, I have yet to lose a campaign... heh.
They are just coming out with a fantasy version called Battlelore, but to heck with THAT since I am
really excited about this new game they are working on that I just got a sneak peak of!
http://files.boardgamegeek.com/images/contests/mattel/pic96.jpgCheers,
Hsta