FF12 is the best title in the series IMHO.
This. Also, don't forget the Gran Turismo games (if you're into that kind of thing).
I like my PS2 better than my PS3, even these days. The PS2 has such an amazing library.
Not to mention it's the size of 3 TV remotes if you have a slim.
PS3 is better at media related things (Bluray, streaming, netflix) but the PS2 just out guns it in "good game" lists.
Both FF X and XII (NOT to be confused with FFX-2!) were great games. Each of them has over 500 hours of playtime in my "best" save file, and that doesn't include all the replays.
Their gameplay is very different, FFX's combat style being turn-based random encounter, akin to Pokemon with hundreds of attack options, and the ability to make just about any weapon and armor you can dream, from swords that can deal all 4 elements of dammage at once to armor that will block just about any ailment you can think of.
FFXII's is real-time and gambit based. You set up conditionals for things to happen, and they happen. You can take manual control whenever you like, but life will be easier if you find good gambit sets and get people in their roles.
Both are loot-based player economy; sell what you don't want.