It's my favourite genre. I think its Xenoblade. About 120 hours.

I like rpg's very much but they do loose my interest after 80 hours or so. Unlike the above.

Diablo 2.

Clocked time must be in the 1000s of hrs. I mean Diablo 3 was a mere blip in comparison and I clocked 500hrs on that.

Disagea, 400 hours.

Then my memory card died.

star ocean last hope 280hrs and going

Dark Souls / Demon's Souls

I've probably played 150+ hours on Dark Souls and 250+ combined on both games.

Resonance of Fate: 135 hrs (single playthrough)

World Of Warcraft.

Played - 398 days = 9,552 hours.

So your true identity has been revealed!

Probably one of the Elder Scrolls games as they never end.

I clocked over 400 hours in Oblivion, 250 on Skyrim. Other than that it's probably Dragon Age: Origins at around 350 hours.

If you count genre mash-ups then Deus Ex is probably pretty far up there although actual numbers are difficult since it released before Steam stats. I played through it about 5 times when I got it and have played through at around once a year since I got it (depending on if a new mod was released). That's not including the time spent playing the multiplayer portion.

MMO: WoW at around 800h
Regular 1 player: Skyrim at arounf 120
Persona 4 at a close second at around 110 - My save file died with my PS3 phat and I never finished it :(