Linux isn't really a good gaming platform at this time. No, let me rephrase that: Most games do not work well on the fully functional Linux gaming platform.
Few games get ported to Linux. UT2003, the Quake series, Wolfenstein Enemy Territory and a handful of others (most ported by Loki software before they went belly up) all work well - as good or even better than in Windows - but most game software houses do not directly target Linux users. Developing for Windows only is so much easier and requires less effort, because - let's face it - the Linux gaming community isn't making anyone rich at this time.
A lot of games work more or less well under quasi-emulators like Wine and its fork WineX. Wine is a port of the win32 API to Linux which means it's not technically an emulator, but rather an implementation of the win32 API on Linux just like win32 was originally developed as an API on MS-DOS. You can go to the Wine or WineX websites and check their compatibility lists if you wish.
I am pretty pleased though. Wolfenstein Enemy Territory is about the only game I play and it's free too.
I don't quite understand why you get put off by Linux as you are a very advanced computer user. Most of us here aren't even halfway advanced and we like Linux anyway.
Anyway, what distribution you should try is entirely up to you. Download a few and try them, settle for the one that serves your preferences best. All mainstream distributions are usable both on desktops and servers so it's pretty much up to you. Depending on who you ask here you'll get different answers as everyone has their own favourite(s).