I'll go with Crackdown.
I really don't get why people like this game, it's one of the most BORING games I've ever played!
And there's Eternal Sonata.
Granted, I do play this game trying to like it, but the combat is repetitive at its best and frustrating at its worst, cutscenes feel needlessly padded, characters are mostly dull (though sometimes have their moments). Yet is has some atmosphere and there are some interesting part of the story, I played through a good chuck of it trying to like it and to get to the story parts, but the actual gameplay was a pain to go through and made it not worth the time.
And there' F-Zero GX.
Bad controls, unforgiving difficulty, frustrating A.I (which I suspect is cheating), overall my idea of among the few bad Nintendo games ever made, and possibly the worst.