How can u play a game like that for so long?

Pokemon SoulSilver: 130 hours 

I have spread my time around too much clearly

Mass Effect 2 about 50 hours
Final Fantasy XIII about 40 hours
Red Dead Redemption about 30 hours
Final Fantasy VII about 40 hours
Final Fantasy IX about 35 hours
Napoleon Total War 32 hours
Empire Total War about 30 hours
Football Manager 2010 about 30 or 40 hours

and probably a few more games that I can't remember have crept up to the 30 hour mark

A lot of time has also been spent with FIFA 10, 2010 FIFA World Cup and FIFA 11, probably over 100 hours between those 3

Oh right, forgot about Pokemon. That's at least 50 hours of my life gone into SoulSilver.

Red Dead Redemption - X360 (50-60 hours.)

Mass Effect 2 - X360 (Approx. 50 hours.)

Super Mario Galaxy 2 - Wii (45-50 hours.) 

Probably Super Street Fighter 4.  I can't understand why.  I didn't really enjoy last year's Street Fighter 4.  All they did was add a few characters that I've barely used and I can't stop playing it.

Second is possibly Final Fantasy 13.  For such a linear game, it was still pretty damned long. 

Halo Reach about 80 hours

Unfortunatly FF13, about 98 hours to get the platinum, next is probabily Demon's Souls with about 93 hours. (Demons Souls only came out this year in the EU so i think it counts).

and Bayonetta, maybe 45 hours max.

FF XIII - 100 Hrs

Kingdom Hearts Birth By Sleep - 45 Hrs

Metal Gear Solid Peace Walker - 40 Hrs

Red Dead Redemption - 25 Hrs

Battlefield Bad Company 2 - 25 Hrs

God of War III - 20 Hrs

Heavy Rain - 20 Hrs

Because it's awesome.

That's more than 95% 1 player too, as the online is a little awkward when I haven't got a Wii Speak so I only spent about 6-7 hours online.

I still haven't fully completed it either, got about 4 of the in-game "achievements" to go, but i'm not much of an achievement whore in the Xbox way (ie all you get for your acheivement is some text/medal saying you did it) which is why I pretty much stopped playing when I had achieved my own goal of finding all the species and treasures.