If you want to do online gaming, go with something like tinyXP as opposed to a linux distro; Wine still sucks.
And as for the browser: stop being so anal about bloat. If you've got 1GB or more of RAM and have a vague idea of how to get your PC running efficiently, you won't notice any difference in how basic things perform if you're running Firefox, iTunes and Azureus as opposed to lolifox, foobar and uTorrent. Want to do some image editing, or something else unavoidably RAM-hungry? Fuck, close your damn web browser. You weren't using it anyway, and FF3 lets you save tabs. Anyone who thinks that NEVER using more than 3% of the memory you have available is a good thing is an idiot.