"Must Have" PS2 games

So, there's a crap-load of PS2 games out there. What are the "must have games"? So far I have Tony Hawk 3 and 4, 007 NightFire, Burnout 3, Katamari Damacy, and Jak and Daxter. What else would be good to complete my collection? I'm a fan of all genres.

Don't forget:

god of war, devil may cry, ratchet and clank, persona, rogue galaxy, tons of other rpgs, shadow of the colossus, ico....

Go here: http://www.gamerankings.com/browse.html?site=ps2&cat=0&year=0&numrev=0&sort=0&letter=&search=

How could I forget about Kingdom Hearts?! And Metal Gear Solid!

All of the Shin Megami Tensei games and FFX. FFX-2 and FFXII are also pretty swell.

god of war 1 and 2, gundam vs. zeta gundam, metal gear solid 2, resident evil: code veronica, burnout series, def jam: fight for NY

most of the best games have been mentioned already so.. Wipeout Fusion, Manhunt, Twisted Metal Black, Gran Turismo 4, Yakuza, Half-life, Hitman series, Psychonauts, Time Splitters 2

What's the best Metal Gear game on the PS2? Oh, and I'm glad someone reminded me of Shadow of Colossus. I've always wanted to play that one.

God Of War 1 & 2, The Warriors, Those Time Splitters Games, Kingdom Hearts 1 & 2 and Those GTA Games