i think that the most under rated game would have to be baten kaitos for the gc i mean it’s the bomb it has it’s up and downs but if u like rpg’s and have a gc u will want to get it. It’s so fun and really long and some parts are hard but thats good because easy and short games are no fun you palyed money for it and you want to play it for a long time and baten kaitos is really long i still have to beat the last boss.
Not too sure about underrated as such but I know a clutch of underplayed (yet critically acclaimed) games- Power Stone, Amplitude, Bombastic and the Granddaddy of them all, Tempest 2000.
Most underrated in my collection at least would IMO have to be Mortal Kombat Deception. I don’t know why this game has such ill will directed toward it- I find it more enjoyable than Tekken and miles ahead of DOA3/4.
I’d have to say probably the most under rated game I know of is Indigo Propecy(spelt wrong I know but I can’t remember how to spell it). Most people would pick it up and say, ‘Oh, another murder mystery game.’ then set it back down. Its actually a very good game with a lot of things you wouldn’t expect. Really the only bad thing about it is that its super short, you could probably beat it in a couple days.
Arrrrrrrrrrrrrr Tales of Phantasia
Final Fantasy 7
Beyond Good and Evil and Legend of Dragoon
The Guilty Gear Series.
I Agree Indigo Prophecy was underrated. i really enjoyed its story and excellant voice acting.
Future Tactics.
Mischief Makers.
Quest 64.
Only thoughtful post in here.
I’m pretty fucking sure that if I read any more of your posts I’m going to develop a tumor. For gods sake stop sleeping through english class.
Anyway, the most under rated game I can think of is Mario and Luigi: Superstar Saga. Man that game was the shit!
I was half-joking, though. 
I suppose it gets a lot of bad rap for being what it is, but THEN on the OTHER hand, it’s just that reason that it ISN’T technically overrated. Final Fantasy 7 is a mystery wrapped in an enigma.
…wrapped in a tortilla.
Seaman
Amplitude is the greatest fucking multiplayer party game out there. It’s incredibly underrated, got no publicity when it was released, and even the prequel got no publicity.
Siren.
Fun, long, and hard eh? Just the way things should be.
The most underrated game I can think of is the Worms series. Its good clean worm killin’ action.
Lufia 2 for the SNES and Magi-Nation for the GBC
I’m replaying Summoner 2 right now, and I’m re-realizing what a hidden game it is. Unless you get annoyed with a million sidequests and the fact that it’s annoyingly easy to get killed, it’s a neat game with a fantastically deep lore and backstory, graphics that could be better but work well, good music and sarcastic characters up the wazoo.
The characters make up the best part of the game; all of them have a personality and more importantly a serious drive behind what they’re doing - not to mention that they’re some of the oddest heroes I have ever come upon. Like a big fat purple toad creature who pretends to just be a stupid barbarian speaking about himself in third person, until it turns out that he’s a god from another dimension. Then he steps up and turns out to be one of the most intelligent people around. He sure doesn’t look it, though. Oi.
Thing is, most people don’t even know about it. Or they’re rightfully scared off by the clumsy first game. Brr.
Mario Teaches Typing. Shit was that fun, and useful. Seriously, if that game had caught on, posts like the first one in this thread would never have been.
Planescape: Torment. I’m really not sure of how it’s rated or what’s the general opinion, but I’ve seen it mentioned like, thrice in all the time I’ve been on the web. This needs more worshipping.