Viva Pinata, Psychonauts and more in GameDaily's article on the most unappreciated games of all time.
Psychonauts (2005, Multiplatform):
Much like Beyond Good & Evil, Psychonauts failed to appeal to the masses, probably for multiple reasons. If you missed it, trot to the local mall and pick up a copy, since you owe it to yourself to experience something wildly original. Everyone should experience psychic summer camp at least once.