Either World of Warcraft or Counterstrike for me. I've played WoW since day 1 in 2004 and CS (1.6 and Source) since 2003. I just added up my /played time on WoW, since I hadn't done so in years, and I have just over 8600 hours logged on WoW and over 3000 hours logged on Counterstrike between 1.6 and Source with 2 Steam accounts. I even played in a league for 3 seasons in Counterstrike. Well over 10,000 hours (more than a full year) spent on just 2 games.
Edit: A friend of mine said all of the time on WoW is probably on 2 characters. 70% of it is on my main and another 18% is on my 1st character (main is 2nd character). The last 12% is littered between 4 alts.
WoW (Proudmoore): Scy - Undead Rogue
GW2 (YB): Scy Fang - Thief, retired
TOR: Scy Fang - Sith Tanksassin, retired
FF14 (Behemoth): Zaya Xuaro - Dragoon, retired
Last edited by Scy; 14th October 2013 at 10:50 AM.