1. Metal Gear Solid 2: Substance

2. Persona 4

3. Ratchet & Clank 2: Going Commando

4. Grand Theft Auto: Vice City

5. Zone of the Enders: The 2nd Runner

this is gonna be tough

#1 Final Fantasy 10

#2 Suikoden 3

#3 Shadow of the Collosus

#4 Metal Gear Solid 2

#5 Dragon Quest 8

1. Final Fantasy X

2. Shadow of the Colossus

3. ICO

4. Disgaea: Hour of Darkness

5. Okami

1. FFX

2. KIngdom Hearts 2

3. Kingdom Hearts

4. MGS2

5. GTA III OR GT4...hard to decide

1. Persona 4

2. Final Fantasy X

3. Kingdom Hearts 2

4. Final Fantasy X-2

5. Kingdom Hearts

#1 Kingdom Hearts

#2 Metal Gear Solid 3: Snake Eater

#3 Kingdom Hearts 2

#4 Jak And Daxter: The Precursor Legacy

#5 Final Fantasy X

If I had 6, I'd put Dragon Quest VIII

This is really hard since the PS2 is my favorite console and there are a truckload of games I love from it but I'll try...

1- Metal Gear Solid 3

2- Persona 4

3- Grand Theft Auto: San Andreas

4- Silent Hill 2

5- God of War

If I could choose more then these titles definitely deserve a mention: Silent Hill 3 and 4, Resident Evil 4, Sly Cooper series, NFS: Underground, Gran Turismo 3, GTA: vice city, 007: Nightfire, Prince of Persia trilogy, Splinter Cell trilogy, Tekken Tag, Tekken 4, Tekken 5, Dark Cloud 2, Persona 3, SMT: Nocturne, SMT: Digital Devil Saga, Devil May Cry series, Spartan: Total War, God of War 2... and the list goes on. Man! there were lot of awesome games on the PS2.

1. God of war 2

2. God of war

3. Ico

4. Metal gear solid 3

5. Legacy of Kain: Soul reaver 2

Looking at other people's lists, there's a ton of great games that I forgot existed!

#1 Final Fantasy XII

#2 Final Fantasy X

3# Persona 4

4# Silent Hill 2 

5# MGS 3: Snake Eater