The Wii in particular is ripe with hidden gems considering how many dismissed it as having no decent games
1) The Munchables (Wii)
The multicoloured, caffeine-soaked offspring of a basic 3D platformer and Katamari. You have to scoff space pirates who are all composed of food while rushing around big lush levels. An absolute treat with a cracking soundtrack.
2) Eledees (Wii)
A weird mix of physics game, shoot em up and hide and seek. Thrown on the casual-crap pile by almost everyone (myself included), later levels require a strategy and time management in order to gain access to the little sods before the time limit ends. Everything in Eledees has a weight, so you can't throw heavy objects to check them for varmints before levelling up. In later levels you start with small items of furniture but end up chucking small buildings around. It's a hoot, with a touching story too.
3) Banjo Kazooie Nuts & Bolts (360)
The game nobody wanted, yet locked under the vehicle tinkering is the same Rare platforming magic that's always been there. A truly quality game in a sea of third-person open-world shooter greyness.
4) Bladestorm: The Hundred Year War (360/PS3)
Though re-released and added-to under the title Bladestorm: Nightmare on newer systems, this remains a slightly flawed but fun sprawling battlefield game ready to kick your butt at a moment's notice.
5) Dante's Inferno (360/PS3)
A full-priced title and certainly not a hidden one by any means, nor a terrible seller, but nonetheless now seemingly out of mind. Wasn't perfect, not enough enemy varieties for my liking, but epic bosses, not least Satan's wobbling Johnson, a terrifying battle.
6) Project Sylpheed (360)
Early release from Squaresoft, X-Wing meets anime, fun game which gets even better with New Game +.
7) Sacred 3 (360/PS3)
Another one which nobody wanted and sank without a trace, but it's actually a fun combat-centred Diablo 3-alike. A little repetitive, but a perfectly fun game.