Some nominations:
Adventures of Cookie & Cream
Adventures of Darwin
Bloodrayne (no really, the first one is good!)
Headhunter (fun near future sci fi action adventure)
Headhunter: Redemption (criminally underrated sequel. ditches most of the adventure for some solid third person action in a twisted Running Man-style world)
Kim Possible: What's the Switch? (classic 16 bit platformer fun with sexy as hell graphics)
Kya: Dark Lineage
MLB Power Pros
Naval Ops: Commander
Tokyo Xtreme Racer Drift 2
Transformers: Armada
Yakuza (why did this not do better in reviews or in the stores? The best parts of Shenmue mixed with the best parts of Spikeout? Win!)
Warship Gunner 2 (Ace Combat on fucking ships. Addictive as hell)

Possibly include:
Culdcept (some of those games can get pretty fucking long. Ok, all of them get pretty fucking long)
Predator: Concrete Jungle (if you can adjust to the camera, it's actually quite fun)

Heard good things about and intend to play:
Bujingai
Dynasty Tactics
Enthusia Professional Racing (hardcore racing sim)
Heroes of Might and Magic (the remake of the first game)
Spy Fiction
Steambot Chronicles