Dirge of Cerberus: Final Fantasy VII (PS2)

Event Viewer
Finish the entire game, eat some beef jerky from the fridge, then save your game. If you load the finished game, you can view the cut scenes, which is quite cool. You get a cutscene for every Memory Capsule you collect, so that means cutscenes for the whole family!

Extra Ending
You must get three G Reports before you finish. Do this and you'll get an extra ending after "The End". And though most gamers would assume that "The End" is in fact the end, sometimes it is not, which where this paradox both begins and ends.

Mission Mode
Beat the game and you will get mission mode, which as the name suggests doesn't involve ice-cream and corn flakes.

Hint: Cacatuar
Before you fight Nero the Sable in the Chapter 10, keep an eye out for some barrels above you as you run on through. There will be four barrels that blow up in a line. One of those barrels contains one of Final Fantasy's best known hidden character "Cactuar". As it falls down to the ground it will start running away and as soon as it gets to the corner it hops on up and disappears. Totally awesome.