bansama: On my eldest daughter's behalf, I'd have to say Pokemon Heart Gold. She played that for just shy of 500 hours and still hasn't completed everything.
She stopped playing it though as she's moved on to Pokemon White U_U.
And it's actually impossible to "catch them all" in the Pokemon games due to Nintendo's on going ploy of hiding several pokemon in each game that can only be unlocked through third party tie-in promotions and competitions.
So unless, for example, you purchased three tickets for the last Pokemon movie before the movie's release, you'd have lost access to 3 pokemon that are apparently required to unlock another. Also, if you didn't download the pokemon that was available via wi-fi during the first month the movie was shown, you've lost access to at least one pokemon hidden in Black/White. Thus anyone who didn't already own Heart Gold/Soul Silver (and watched the movie) will never unlock all pokemon in Black/White.
They also hid a pokemon in Black/White that is only accessible until Oct. 18 when they stop providing the wi-fi download of the object required to access it. Goodness knows how many others they've hidden in there.
Give me a nice game of FUEL any day. That's probably the game I've spent the most time playing in recent years.
How is she playing White, does she speak Japanese?
I know it's pretty hard to catch "them all", but I think a few hardcore folks that have been playing since generation 1 have managed it in most games (since some of those rare pokemon get given away more than once, like Celebei). Even unlocking the entire regional dex is a horrid PITA. My daughter just beat Red this morning in Heart Gold, she was ecstatic.
Yeah I wasn't going to count MMOs, obviously you can plow infinite amounts of time into those.
