What PS2 games do you feel everyone should of played?

I missed out on a lot of PS2 games, so I'd like to see what games you guys think are must plays.

Original Timesplitters.  Man, I loved that game. 

God of war 1 and 2, Shadow of the colossus and RE4.

GOD OF WAR 1 and 2!! I just got shadow of colossus, havent played it yet, but is highly recommended by many. sly cooper, older ratchet games, FFX, kingdom hearts2 if you like RPG's.

Ratchet & Clank: Up Your Arsenal... in fact, the whole series.

As Shimbibby said the Sly cooper games are pretty good. I think I liked #2 the best.
Jak 1 or 3 also fits along the same genre as the others. Jak 2 seems to get the most accolades but I liked that one the least.

My recommendations are Final Fantasy X, God of War 1 and 2, Kingdom hearts 1 and 2, MGS2 and 3.

I hear SoTC is one of the best

MGS:  The Essentials,  greatest series in gaming history.

I'm playing Shadow of the Colossus right now, and it is pretty interesting so far. I'd reccomend it.

Shadow of the Colossus, Jak and Daxter, Persona 3, Okami, MGS3, Bully...and there are plenty more.

Shadow of the Colossus, Kingdom Hearts, Okami, Final Fantasy X, Metal Gear Solid 3

"Shadow of the Colossus, Kingdom Hearts, Okami, Final Fantasy X, Metal Gear Solid 3"

Any of the Shin Megami Tensei games.

"Any of the Shin Megami Tensei games."

I just bought a ps2 off my friend for $35. the original phat one, but ehh at least it stands vertical. 
 
I want to play persona 3 FES alot. Why I bought the ps2 in the first place. I sold mine before persona 3 came out, but loved the first 2.
I'm gonna hold off on GOW 1 & 2 for the HD release. 
I'll probably buy FF 13, so maybe I'll try X. Is 12 any good? Never played a FF game after the SNES
 
What still stands up today?

Resident Evil 4 and Silent Hill 2!

Yakuza 2

My PS2 recommendations are:
 

• Zone of the Enders:  The 2nd Runner.  The game conveniently contains a summary of the story to the first ZOE, so there's no need to play it to understand the story.
• Metal Gear Solid 2 & 3
• Persona 3 FES & Persona 4
• Final Fantasy X and XII
• Kingdom Hearts I and II.  Also Re:  Chain of Memories, if you haven't played the GBA version.
• Fatal Frame I, II, and III
• Silent Hill 2
• Street Fighter Alpha Anthology

God of War 1 and 2, Shadow of the Colossus, Okami, Bully, Silent Hill 2, Tekken 4... the list goes on. PS2 was a great system with an incredible lineup of games and there's so much great games you could of missed on. 

ICO.