Been a die-hard PC gamer for about 10 years now, but since I bought an Xbox 360 earlier this year, I've bought 12 Xbox 360 games and I haven't bought a single PC game.
As for me, the best platform for fun games to waste time on are consoles, simply because that's what consoles are made for. You put the disc in, no installation, no configuration, just play it. Exactly as it was intended to be played.
I'm not that interested in modding, since I often happen to prefer paid professionals' content in the original game above amateur mods.
However, I do play iRacing, RBR and LFS on this PC, since those would be worthless on a console, because of the lack of CPU power for physics calculation and lack of support for the G25 (except the PS3). I've bought this PC mostly to be able to do HD video editing and audio/music production.
As been said before, the games/sims I do play on my PC are those that have a long life and are in-depth. All other games go straight into my XBox 360 tray.