If you liked MGS2 , you will LOVE MGS3 , even MGS1 more. MGS4 is definitely badass, I really wish they would release a new version like they always did , with trophies and new stuff.
Best PS2 games:
God Of War trilogy
MGS2 and 3
Final Fantasy X
Gran Turismo 4
Devil May Cry 1 and 3
I played to every games you list here except MGS3 (I have it but will begin it soon) and Devil May Cry 3. I played the first DMC but my lack of reflexes made it a little frustrating for me (just to make you laugh, I usually play God of War and similar games on the EASY option). Why the second one was not worthy?
Except for the latest one for PS3 I played almost EVERY Final Fantasy game!
FF I-II on the Gameboy Advance (boring, both of them)
FF III-IV on the Nintendo DS (nice, very nice, I liked them)
FF V (I have it for GBA but never played it)
FF VI for the Gameboy Advance (yeah! very good indeed)
FF VII on the PS1 (the one that started it all for me! Masterwork!)
FF VIII on the PS1 (same as the VII)
FF IX on the PS1 (just a little less entertaining for me but I played it in a period of my life where I was fed up a little with videogames in general)
FF X on PS2 (I liked it a LOT)
FF XII on PS2 (maybe the best of all, up there with VII and VIII)
FF Crisis Core on PSP (didn't think they could replicate the feel of VII so well and update it but they did it)
FF Tactics on PSP (an endless strategically varied piece, still playing it from time to time).