Metroid: Other M certainly had an assload of potential that may or may not have been overshadowed by the story segments and people reaction to them. There are so many things right about that game, it could have been huge.

On the older side, I'd pick StarFox Assult. It was almost the true StarFox sequel we wanted, but just a little to spread thin and a little too on Gamecube to be that great successor to StarFox 64.

I'm going to pick Red Dead Revolver.  Even though this is one of my funner game experiences in, well, pretty much forever, the overall game just seemed like it had SOOOO much more potential than it provided.

Knights of the Old Republic 2 had such an incredible story and such good characters, but was hampered badly by being rushed to the market with a ton of bugs and having a large amount of content cut.  I still loved the game, but it was a shell of what it could have been had they taken their time.

But you have to give him credit for Populous, which was an awesome, well done game, incredibly innovative and influenced the whole industry a lot.

Don't know if I would call it the biggest missed potential even on Wii, but I think Zack & Wiki could have been much better. I loved the idea and liked the presentation. Some of the puzzles were good, but it was just too much trial and error, and each item had anly narrow use.

Cursed Mountain: It had some good elements and all the makings of a decent horror game, but the Wii controls completely ruined the experience as they just didn't work at pivotal moments.

Knights of the Old Republic 2: Great game, but unfinished so the end felt rushed. If only they'd had more time.

Deus Ex Invisible War: They took the greatest game ever made and over-simplified the experience. So much potential and a potentially great story let down by dodgy design decisions, small areas and general consolification.

Dragon Age 2: Another case of over-simplifying the sequel to appeal to a broader audience, only to gimp the experience for fans of the first.

many games that came out for the Wii have this quality:

Mad World, Zack &Wiki, Crystal Bearers, Other M, Fragile Dreams, Epic Mickey and so on.

I can tell you one thing though: none of them failed to live up to their potential due to choice of platform!

Defnitely MAG. I really like MAG though...I just think it could have been amazing...ya know THE GAME TO PLAY, but it wasnt. I probably played it more than any other online shooter other than BBC2. I am about LVL 56 in MAG and to be honest it took me that long just to really get what was going on most of the time in the larger games and maps. 

Well said, it really is up to how much effort developers, are willing to put into their games.

DA2 is an easy pick. Give it another 8 months development time and it would have been an awesome game.