Personally, I see Linux gaming stuck in the Win3.1-Win95 conversion era. Not a whole lot of commercial titles, but some. A ton of free titles on various sorts and differing quality. We have drivers for most of the latest in 3D cards, sound card, input items, and the like. Not everything works 100%, but it's getting better.
When going for the commercial games, don't forget the full impact of having some of these game running under Linux gets you. For instance, Q3. There are hundreds of mods for it, both partial and full remakes. The same goes for UT and several others. These mods bring a lot of new like to a tired game. Then there are other commercial games that have gone open source which enables them, games based on the same engine, to be moved over to Linux.
In the free games, there are a good number of exceptional titles. The problem I have found, like many free games on the early Win95 platform, is that many are abandon or require some obscure bit of software to get them working. One really needs to sift through a lot of bracken to find some treasures hidden in the pile.
