Lots and lots of Pokemon on GBA and DS, easily over 100hrs on Sapphire, Ruby, Emerald, LeafGreen, Diamond and HeartGold each, and the GBA games I would play over and over with many 100hr+ saves, easily 1000-1500hrs across the whole series
Other than that:
Advance Wars: Dark Conflict
Final Fantasy XII: Revenant Wings
Dynasty Warriors 7
Dynasty Warriors NEXT
Star Wars: Knights of the Old Republic (across multiple saves)
Battalion Wars 2 (hazy on this one but I'm pretty sure I got to 100hrs with multi included)
Super Smash Bros. Brawl
Mario Kart DS
The Simpsons: Hit and Run (not sure, played through it 3 or 4 times when I was younger including a 100% completion once, also played at friends' houses so may reach the mark)
EDIT: Oh, and how could I forget both Star Wars: Battlefront games! I also played some other shooters on OG XBox a lot as well (particularly Star Wars: Jedi Outcast and Jedi Academy, as well as 007: Nightfire). JO and Nightfire might be 100hrs plus (gotta love that bot mode) but again I can't be certain
