Loki games (nonexistent now) has a ported version of SimCity 3000 Unlimited for Linux. The Windows version of it was very popular. I remember sitting hours together building a simulated City, laying a bit thick on finding solutions for the disasters and problems that surfaced on the simulation ;) Thank goodness, I never had my own computer then... otherwise, "hours" would easily have been "days" - such is the addictiveness of this game.

Recently, there have been a multitude of games that not only run efficiently on Linux, but are as good as the Windows versions. The last one I tried was a demo of Doom (the latest version I guess), and it worked real smooth. The same is with Quake, America Army Operations (all run pretty well on Linux). Ubuntu itself comes with a range of lovely arcade games (not by default, one has to download from its universe, multiverse repository). Maybe the coming days would really see Linux as a choice for desktop in day to day usage. :)