I don't know which one, but definitely Pokemon. One of my files had 125+ hours on it. Yeah. That's a lot of time for one game.

Mario without doubt. Always each time you play it is impossible not to play this game. With more time consuming but very pleased. When you play this game loses time but added pleasure.

My most played game is Sonic 3 and Knuckles. I don't know, I just love the game to pieces and find myself playing it all of the time.
I've beaten the game like hundreds of times and I don't even think it's possible to state how many hours I've played.

I've devoted the most time to World of Warcraft hands down. 

I've easily spent over 300 hours on that game. But in defense of my social life I've been playing the game for over 2 years, so I've had a lot of time to accumulate the time.

The game's got so many expansions that it really never "ends" so gathering hours is pretty easy.

Probably Dark Souls, i've got a level 78, 120, and 483 for different purposes in the game, it's not even slightly difficult for me now that I know the in's and out's of the game and it's mannerisms, mostly I just use it for PVP now days, soon it's sequel shall be my new masochist mistress, lmao.

I've played Runescape from 2006-2011. I really liked it because it had lots of gameplay in an online game that you don't even need to download. I didn't really care about the graphics since I really liked the gameplay and meeting people from the online world. The skill building and combat got me motivated to play everyday. Even though I was a no life for that game, I had pride in playing it everyday.

Sadly, Runescape isn't what it is to me a few years ago. The gameplay is now slacking off and the graphic are getting better so the game pretty much switched places from having good gameplay and bad graphics to good graphics and bad gameplay. It has been slacking off that many people liked the old Runescape a few years and they play old school Runescape by paying for its membership.

Spending lots of time in a game can really make you an expert.  

If I'm honest? Probably Paper Mario. I didn't mean to, honest! I just used to end up spending over 100 hours trying to beat Huff N Puff...
Not counting that, it's probably Super Smash Bros. Brawl, because there's so many achievements to get.

The most time I've devoted my life to was Burnout 3: Takedown, I've had it for nearly 10 years (this year in September it will be 10 years).

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