Games You Just...Can't...Put...Down.

internet checkers

Deus Ex: Human Revolution.

torchlight 2

AoE II xD with my boyfriend we play hours and hours

Saints Row series(2 in particular, just wish it ran better)

Batman Arkham City and Deus Ex HR. The only ones of my games that I have (attempted) to playthrough twice

Farm Franzy and Treasures of Montesuma. The latter is btw way much better then Bejeweled 3, so if you don't mind, vote for it on Greenlight :)

uhm sex

and hl2: dm

I really experienced this with Dark souls. When I play a game I like, I usually spend an hour or two but then get bored and need to take a break.
But with this game, hours seem much shorter and I only realize it's time to stop for a moment when I spend consecutively 4 or 5 hours playing it.

for me its league of legends lol^^

DOTA !!!!!!

If so, I wouldn't be able to write this comment.

But seriously, nothing I can't put down easily, games seem more boring these days.

Skyrim or minecraft