FFX, check.

FFX-2, the gameplay outweighs the plot flaws.

Suikoden III is nifty. Epic plot, although I found the guy tending the castle more interesting than the three main heroes. Two honorable villains worthy of Rubicant.

Suikoden IV is quite a change from the rest, especially in the way (SPOILER)a boat becomes the home base instead of a castle. A lot of time spent traveling. I liked a lot of the characters, although a few are very hard to recruit without a guide. It's also one of the few Suikoden games where you can max most of the characters (leveling usually becomes ineffective above level 60).

Suikoden V is a return to the core values of the series. A lot of royal dynastical infighting and intrigue. Some very loveable secondary characters.

There are several others I recommend that date from the PSX console: Breath of Fire III, Dragon Warrior VII (although mastering is recommended only for the masochistic), Suikoden I & II.