If you're as big a freak as I am, you keep track of what you've finished. Doesn't have to be 100% completion, just played to the end.
Grandia 3
Need for Speed: Hot Pursuit 2
Devil May Cry 3
Starfox Adventures
Ys: The Ark of Napishtim
Dragon Quest VIII
God of War
Thief 2
Baten Kaitos
Zone of the Enders: The Second Runner
Tokobot Plus
Half-Life 2
Disgaea - Hour of Darkness
The Legend of Zelda: Four Swords Adventure
Digital Devil Saga
Katamari Damacy
Demon Stone
P.N.03
Wild Arms 4
Grandia 3
Need for Speed: Hot Pursuit 2
Devil May Cry 3
Starfox Adventures
Ys: The Ark of Napishtim
Dragon Quest VIII
God of War
Thief 2
Baten Kaitos
Zone of the Enders: The Second Runner
Tokobot Plus
Half-Life 2
Disgaea - Hour of Darkness
The Legend of Zelda: Four Swords Adventure
Digital Devil Saga
Katamari Damacy
Demon Stone
P.N.03
Wild Arms 4