Again Star Wars for me is probably the all time fave.
Have to mention Crossbows and catapults mind. Superb destructive fun, build your castle up with the big plastic bricks, hide your men about the place then go hell for leather at each other until you either land a bolt on the opponents treasure or all the little men are dead. Used to have about three different sets and have four way battles.
Absolutely class that, a mate bought it off Ebay not long back and we spent a long weekend playing it constantly... pure magic. We cheated a bit and used Jenga pieces to reinforce it a bit, you could create some insanely indestructible structures with that.