Ahhh, the classic ToeJam & Earl.  Where to start about this game...first of all, it is one of the funniest, most enjoyable two-player experiences ever created.  I grew up playing this game with my friends EVERY day and never got tired of it; to this day I still play it all the time.  This game introduced the funky alien duo, ToeJam and Earl.  It's a cooperative adventure game based on searching for items and exploring each map.  The maps and presents are randomly generated so the game never gets boring.  The presents are the best part of the game.  Around each map you'll find presents scattered all around.  The first time you open a present with a particular wrapping you don't know what it is.  After you open it, you will always know what that kind of present is.  However, if you open a randomizer present, the presents are mixed up again.  If you open a present with your partner on the same screen, you both get what's inside.  It also has a promotion system where you advance from a lowly wiener to a high and mighty Funklord.  It serves the purpose of giving more lives and increasing your life bar. 
The storyline goes something like this:  ToeJam lets Earl drive (big mistake) and their spaceship crashes on planet Earth.  Their ship is blown apart and the ten pieces are scattered all over the planet.  Now they have to hunt them down so they can leave that crazy planet.  It really doesn't matter how many ship pieces it blew into, since the game is always 25 levels anyway  :).

Presents
Earthlings
Food