I got this idea from a poll in civ5 general discussion asking how many hours people had played on civ5. I was curious, what are your top played steam games and how many hours? You can check this by clicking on your profile, selecting games and filter all games and by hours played. Mine's a pretty weird list when I actually think about it. I didn't list anything under an hour (I have a ton of games I loaded and played for 20 mins and haven't sat down with yet). First I can't believe I actually spent so much time on darkspore... I love it personally but am still amazed it kept my attention so long. And plants vs zombies really surprises me because I never sit down and play this for a whole session. It's the game I play when I have 20 mins before I have to go do something. I guess a minute here and there can really add up. I spoilered the ones outside my top 6 cus it's quite a list.
Dota 2
357.9 hrs on record
Space Pirates and Zombies
184.2 hrs on record
Darkspore
175.2 hrs on record
Sid Meier's Civilization V
166.7 hrs on record
The Elder Scrolls V: Skyrim
92.1 hrs on record
SimCity 4 Deluxe
62.9 hrs on record
Dota 2
357.9 hrs on record
Space Pirates and Zombies
184.2 hrs on record
Darkspore
175.2 hrs on record
Sid Meier's Civilization V
166.7 hrs on record
The Elder Scrolls V: Skyrim
92.1 hrs on record
SimCity 4 Deluxe
62.9 hrs on record
Spoiler: