All time #1
WARBIRDS - before they killed the lower realism mode. I was even a Squadron commander at one time ("The Drifters, Guns for hire") with about 30 members. Was always an awesome time when we got together!
#2's
DIABLO II - spent way too much time on this. had 48 characters, all level 80 or above, with 6 level 99's. Sold the acounts on eBay
SH III - Mostly because I'm playing it now... but probably won't remain. Fun, but not THAT fun. Maybe if they had better multi-player options, including a "no friendly fire" option that would prevent hack weenies from causing damage (or better yet, have any damage that would have been assessed, be assessed to the shooters sub and not yours).
Other notable:
REAL WAR - fun, and a bit challenging, but not an all-time favorite. I think there's a newer version out there (something like CIV 4, but with tanks and such -- if you know of the game I speask, please PM me) I seem to recall something on the G4 channel that reviewed this game - but I forgot the name
maybe Age of Empires III ?? :hmm: I'm not sure how far that game goes.