Xenogears: It's a really ambitious game for its time and it shows with an incomplete 2nd disk (that mostly involves chairs, slide shows, and highschool level dramatic reenactments). It was also intended to be part of a much larger series which also never happened (there are a lot of details the game basically winks at and suggests that there's a lot more to it than they're telling you but you'll never know because they'll never cover it). And the localization was pretty dismal so a number of details also gets lost in translation. Other complaints involve the fact that there are a few areas that are rather difficult to play through (like Nocturne's Sewers or the Tower of Babel or that particular double whammy boss rush during disk 2). That said it's probably worth at least one go through just to see what it's all about and if you like giant robot anime then you might like the homages and borrowed plots from them (and if not well you'll get to see something new).
Vagrant Story: Fun game, even if it's a dungeon crawler. It does require you to figure out how its complex systems work to minimize grinding. Platforming can be a pain at times though. Plot's interesting, but again nothing comes of it despite the suggestions (that its merely a prologue for the real game that never came). Again, worth a playthrough just to see what the fuss is all about.
Grandia: Was never a big fan. Mostly due to having played through Grandia 2 and seeing what it's all about from that. In my opinion, if you've played one Grandia game you've played them all. I'll give credit for trying to run with a lighthearted adventure romp but it degenerates into generic and uninspired JRPG trash (but then again, every Grandia game save for Xtreme and 3 does this in which the former doesn't even bother with a plot and the latter dispenses with the trying not to be painfully generic and uninspired at the start even though it still manages to go downhill from there).
Parasite Eve: I'm almost willing to say that mechanically speaking, this game is basically a predecessor to what Vagrant Story did with its gameplay (except for making Bazooka shooting Shotguns instead of Swords that cuts skeletons, bats, and things weak to earth better than a Mace that crushes humans, lizards, and things weak to water and/or fire). Plotwise it's as entertaining as mutant monsters take NYC, so if you like monster flicks then it might appeal to you.
Alundra: Have not tracked down and played this yet.
Suikoden 2: A bit overrated but a solid game. Mainly benefits from the fact that it's part of a interconnected series that spans six games. Unfortunately the series kinda loses its direction by the third game so don't expect a resolution to any of the major questions hanging over the series. Still a fun game even if its buggy as hell and requires a guide and almost perfect planning to 100% in one or even two runs.