I have over 100 hours on Kid Icarus Uprising --- 3DS FC: 4940-5445-8767 It is a remake, not my fault you people think ports are remakes (but only on Nintendo systems)-Demondog666 on Kid Icarus Uprising
Samurai Warriors: Chronicles Tales of the Abyss Kid Icarus: Uprising
I'd say those 3 games have more than 100 hours worth of content.
Mario Kart 7 can also give you 100+ hours if you enjoy it enough. As for Dragon Quest 9, you shouldn't have much trouble reaching 100+ hours. The game itself is about 30 hours, but the post-game stuff takes quite a while.
And I suppose there's also Pokemon Black & White (and the 2nd games of them). They can last 100+ hours easily too. --- Read the mania: http://www.fanfiction.net/~nonexistinghero In SA2, it's Super Sonic and Hyper Shadow.