Well I got addicted to Wow a few years ago, threw in there over 150 DAYS played time in it (3600 hours). Doom 1/2 is still my record (back when it came out late 93 start 94), over 7 years I poured possibly up to 7,000 hours into the game. Go the starting age of mods :)
EDIT:
I've thrown 100+ hours in the following games
FF games (DS,PS,PS2,PS3)
Quakeworld (to be honest I've possibly played this more then WoW :S)
Indy 500 (1989 game!)
chrono trigger - snes
Sonic 1 - Master System (although playing through took about 40 minutes, I basically played and clocked the game every day I had it until my MS died)
few others that I can't remember no doubt