Psychonauts the best game that nobody played is Now Available on STEAM. I don't like forwarding you to Valve, but Psychonauts should have done much better commercially than it did. Apart from having excellent voice acting and characters, it has spectacular level design that will delight you from start to finish. Well worth purchasing if you haven't played it. I am not saying the game is perfect, but it should have done much better at retail than it did.
When I first finished playing through the game I wanted to write a review, but didn't want to spoil anything for anybody who hadn't already played it. So instead of a review I posted This Quote which sums up perfectly what I felt at the time and still do now for the game.