Everquest 1999-2004 average 3 hours a day. (probably low balling it, 30-36 hours in weekends was not uncommon)

I'm not sure which one, but I'd say Skyrim, Pokémon, or Final Fantasy X. These games consumed me for weeks.
Fire Emblem Awakening is not too far, and I think I also spent 90+ hours on Game Dev Tycoon.

Destiny of Spirits: 965 hours so far.

Heh.. I had to spend more than 100 hours with LoL due to my asshole friends!

An MMORPG called Allods Online. I spent approximately 2,000 hours on it over three years.

WoW

I'm afraid to look at /played.

Not sure if Runesape counts, but I've played that game shit tonne before, think last I checked it was around 250+ days of gameplay, plus additional 100 on top I guess (Very generous approximate). It's my fallback game when life goes to shit, grinding just seems so much better.

So at least 300*24 hours.

Team Fortress 2: 1823 hours
Runescape: 1500~

Others I don't know but Age of Empires II and Civilization IV can easily be into the thousands.

Resistance 2, Resident Evil5, Final Fanasy IX and Tactics 1000hrs easy for each.

Of all time would have to be Soldier of Fortune 2 Double Helix multiplayer. I would think somewhere around 2500 hours over about 4-5 years.  I have played prob 1000 hours of Quake 1 in the 1990's, and 500 hours of Battlefield 2 and Battlefield Bad Company 2 also.