[quote name='Dmonrei']Grandia Xtreme is completely different from the first game. It's got the worst story among the Grandia series along with some questionable dungeon choices (not to mention one of the worst VA's for a RPG), but it does one thing good: Focus on the battle system. I personally think that Grandia 2's battle system is the best in the series (and is one of the best RPG battle systems), but Xtreme is a close second to it.[/QUOTE]
Never played Xtreme -- and don't think I ever will.
Agreed that Grandia 2 is awesome, but having played 2 and 3, I have to say 3 is better. It refines the system and adds quality presentation on top of it.
If you can pick up Grandia 3, highly recommend it. As for Grandia 2, I would recommend the DC version since the PS2 version is allegedly a bad port. Though if you have no DC, the PS2 version is the next best thing.