Started with Unreal because I was interested in the editor, but stayed for the game. Played well even on lower end systems. And when Unreal Tournament came out, loved the hell out of it and stayed for the rest of the series. A lot of fun, many maps, mods, alt-fire modes, teleport, and even portals. Didn't have friends that played, but there was always someone online. Unreal engine always felt ahead of its time. And the tools were fun to use.