Starcraft still rocks for me, Dragonshard was pretty fun as well, wish they had of added more to it, and nothing beats Stronhold Crusader for medevil castle builders, the new Stronghold Legends coming out though is a major disapointment, too bad.
Warcraft III is a blast at LAN parties. If your computer can handle it Company of Heroes is awsome it comes out this tuesday (September 12). I've been playing a demo and artillery strikes are a riot.