Personally, for table-top (strategy) gaming, nothing beats a game of Mordheim. It's Warhammer Fantasy in a much smaller squad-level scale. Simple enough to get newcomers interested and for veterans to transition to WHF or WH40k. Plus I've been working (on and off) on a WWII conversion ruleset for the game, since the ruined cities would be perfect for a squad-level Stalingrad battle.
As far as historical games go, DBA is fun, but there's really no variety in units. A unit of Hundred Years War Blades is the exact same as a unit of Early Roman Republic Blades. Still, it's really the only game my father plays frequently, so it's all good.