Love it or hate it (or have just never heard of it), Noby Noby Boy deserves a spot (albeit a high one) on the the list for its sheer oddity. As the extendable caterpillar-like Boy, you have to help Girl stretch across the length of the universe, which is dependent on syncing up your personal interactions in NNB's aimless game world with the rest of the world. Uh, yeah.
50. Noby Noby Boy