Xenogears, hands down. Best darn storyline of any RPG I've ever played, although I hear Suikoden II rivals it.
Considering that all of those are playstation games, I'd reccomend a package deal. You're twice as likely to like what you get if you get twice as much afterall. I personally would reccomend trying Final Fantasy Anthology out for size. It includes both FF V and VI and while I haven't played much of V, VI is superb. FF VI has fourteen differnt playable characters, a wonderful plot, a flowing battle system and plenty of freedom in the second half of the game. The music isn't half bad either and infact, I'd have to say that is indeed an understatment.
However, you might want to steer clear of it if you don't like 16 bit, 2D graphics because that's exactly what both games in Anthology are. The reason for that is of course that both games originally came out on the SNES so they had to conform to SNES standards. (Anthology itself is for the playstation of course so you don't have to worry about compatibility issues.)
For a 3D game, I'd reccomend FF VII. Logically it's one of the only 3D Playstation game left in the FF series and has plenty of touching moments. Materia is interesting and the plot can be quite involving. It's been a while since I played though so I can't say much more about it though. . . Oh well, I doubt you'd regret getting it.
Well, those are my recomendations. I hope they help you come to a decision.
Look, I'm a strange person. When I was younger, nothing used to make me laugh any harder then when somebody made fun of me. Unfortunatly for me, my mockers looked at me strangely and stopped when I did this. Go figure.
I recommend any and all of the Final Fantasy games (Except X-2). I also would recommend Kingdom Hearts.
...However, I demand that you go out and buy Xenogears right now!!! It's truly an incredible game. One of the best ever made in my opinion.
Oh, man, I totally forgot about E.V.O.: Search for Eden. It's phenomenal, really.