I got addicted to one of the final fantasy games and was playing the game for a few hundred hours in total.

I'm up to 240ish on Persona 4 but I think I've got 500 total on Oblivion and 300 on Fallout 3.

orignal CS : since lauch. and i do mean beta made in the garage before it was a retail game lol. 
starcraft (first one) : about 10 years 
multiple FF games. 7 was probably the most time on those at like 200 hours over 2 or 3 saves. 
team fortress 2 i am up to like 150 hours but have played it many more hours than that before it logged my time played. 
ultima online for like 6 years. 
ff 11 for 2 or so years. 
WOW for like a year total.. what a waste that was lol.  
lfd 1 and 2 prolly 200 hours total. 

I have 169 days played on my Warlock in WoW.  Thats over four thousand and fifty hours.  You can probably add another 30+ days for various alts which means WoW was a five thousand hour game for me.  eep. 

I've spent over 1000 hours in both FO3 and Oblivion. 
 
@Nayson said:

" I have 169 days played on my Warlock in WoW.  Thats over four thousand and fifty hours.  You can probably add another 30+ days for various alts which means WoW was a five thousand hour game for me.  eep.  "

That I can recall... I think FFVII has around at least 160 or so... I have about 110 on FFX-2, around 200 on FFX, 150 on Fallout 3, and my Persona 3 has around 125 now I think... 
 
Wasted youth I guess you could say.  But I've seen some awesome scenes!! Lol.

Probably WoW and Guild Wars if MMO's count. If not then basically Bioware and Bethesda RPG's.

Counter strike source, two years in a row all day. Ppl where very hostile, it ruined my brain, I don't play online games anymore because of it.

I know I have 100+ hours on both Fallout 3 and Oblivion.

I have 610 hrs on record for TF2, if you counted Day of Defeat + DoD: Source together it would probably be higher, actually DoD:S might be higher but I don't think they started counting the hrs until they made the switch to Steamworks.