I am still collecting PS2 games. Yesterday I beat "Dark Cloud" and soon afterwards picked up "Rogue Galaxy". Sometime this week I may also purchase "Dragon Quest 8".
On my shelf that I have yet to complete: "Ratchet: Deadlocked", "Xenosaga", "Onimusha", and "ShadowMan2".
And then there are the games I will return to once every decade. This games include: "Okami", "Way of the Samurai", "Dark Cloud 2", "Ratchet and Clank 1-3", "Wild Arms 3", "Grandia 2", "Guilty Gear X and XX" (I will play those multiple times), and "Shadow of the Colossus". There are also a handful of PS1 games that I play every second coming, but I'd rather not list them all.
Lastly, these are PS2 games I intend to get in the long future: "Ratchet and Clank: Size Matters", "Ico", "Red Star", and a few others I cannot for the life of me remember off of the top of my head.
I have other PS2 games, but they will either gather dust on the shelf until I get some hidden urge to play them again, are sent out to friends for their games, or eventually sold.