PCs utterly destroy consoles. Sadly, most games are now crappy console ports, which also seriously holds back the graphics on the PCs. I mean, after 2 years, no game comes close to crysis in graphics. So I've not been playing any games for along time now.
If you get into the technical side then consoles can never beat PC gaming.
Butttt despite this consoles seem to be pretty popular so it comes down to a preference. I tend to prefer certain types of games on different formats.
Racing games, platformers and other arcade-style games I'd probably have on console. Wipeout HD is pretty awesome on PS3, lol.
RPGs and MMOs definitely remain in the PC domain for me. I play World of Warcraft and it would be entirely impractical to play on a console control pad (hence why Blizzard have never released it for consoles).
Strategy games (your Command & Conquer or SimCity type games) again should stay on PC. Although recently EA seem to be butchering the genre to make them easier to play on consoles. The older ones you definitely have an advantage with keyboard and mouse.
FPS games (Call of Duty, etcetera) are better on PC. However due to the popularity of consoles I am forced to get Call of Duty 4 on Xbox 360 because all my friends play it on that. Infidels.