I really enjoy games. Not so much the competitive kind, I played Half-life in high school and eventually got sick of "smacktards" and so I don't really play online games anymore. I do enjoy LAN games with friends, and really good single player games. Unfortunately, there's not very many good ones for Linux. A lot of games will run under Wine fairly well (Diablo II, Battlefield 1942), and some even run natively (Neverwinter Nights, Doom 3 to name a couple).
My problem is that I have yet to find any really good action-RPGs like Diablo II or Oblivion for Linux (and I do a fair amount of searching for games, see FreeGamage). The RPGs that I do find are usually old, like Final Fantasy III or Chrono Trigger style. While these games are good, they're hardly something that I can do anymore when I have to work 40+ hours per week and then do things like laundry and dishes (and write blogs) in my spare time. I like games where I can go in for a half hour to an hour and screw around for a while. Maybe level up my character, or do a couple quests.
Many people would say "Oh, Linux has games like that, look at Eternal Lands or Planeshift." While I respect the amount of effort and creativity that have gone into these games, they are getting old, they are still in development to the point of being mostly unplayable, and they're boring. As a gamer, I need flashy things happening fairly often in order to entertain me. I don't really like having to walk around a world for extended periods of time, just to kill rabbits (which are a huge pain in the ass to click on, user-interface people!) or wander into a territory where after 3 seconds of seeing the loading screen gone some huge monster bites my head off and I am now sent to a death realm or something equally annoying.
My hypothesis: Linux is lacking in games. At least good ones. I have found a few, like Battle for Wesnoth or Sauerbraten that were able to keep me going for a while, but for the most part I really have not been impressed.