I actually played World of Warcraft for the arena tournaments!
I played the Paladin class, which was the worst class in game (at the time). I was actually the highest rated Paladin playing Paladin/Warlock/Priest, in 3v3, in S3, in the world!!!
I wanted to try live tournaments but one of my team members couldn’t commit and there’s no way I would bother playing with anyone else. Once everyone started playing my comp, the Paladin was quickly replaced with an OP healer like Druid/Shaman, so I quit. It didn't help that the game was so unbalanced either! Plus I couldn't be arsed spending half my life running instances to get competative loot! 
Just don't go there with me, arenas ruined the game and started all the imbalances. To get good loot in PvE nowadays it is so not even half your life (now), you can do with 5, 10 or 25 people in 30-60 minutes (half of them braindead and watching TV at the same time) today what a 5-6 hour 20 OR 40man raid (of skilled players who knew and understood their class) required back in the day. You can thank that to Blizzard arena-izing/tokening the raid dungeons and heroics.
I played WoW since it came out with a bunch of friends until about September of last year. At the end I had 3 lvl 70s and a couple lvl 60s that I didn't bother leveling up in the expansion. I was doing PvE end-game raiding on PvP servers. The first expansion didn't really improve my main classes (PvE raiding mage (leet glass-cannon that just kept getting balanced/nurfed) and a holy dwarf priest (shadow priest post-BC
, frigin' druids!)), and the second expansion didn't look like the developers were even listening to us before they did a bunch of stuff wrong.
EDIT: I suppose COD4 on the xBox counts.
No, only WaW
I was over at a friends house at about 3am after a night at the bar. He shows me CoD4 on xbox live...so I log on and start trying to kill things while the room's spinning. Within about five minutes I was getting ear raped by 12 year olds. I felt more than obliged to give it back AH style! 
Upgrade to WaW and move up to being ear raped by the 25-45 year old drunks that play at about 3am. The 12-yo Aussie squeekers are just too easy.
