PixlBit

I'd say DBZ Budokai Tenkaichi 2. Still the perfect DBZ game in my mind.

I did play that one, though only in small bursts at a friends place. Seemed cool. Do you know if it holds up okay?

I have it on Wii and it does. It's not terribly deep for a fighting game, but enough that the game's enormous story mode will stay fun to the end. Also Budokai tournaments are a blast if you have people over.

Hmmm, I could probably come up with a bunch here. But, for today, I'm gonna say Rez.  

Also, I think DQVIII doesn't get enough props.  

Still haven't played Rez. May have to rectify that soon!

You should definitely rectify that. Also, be sure to check out the spiritual successor, Child of Eden, which is also amazing.

Culdcept jumps to mind. Want to go play it right now. It's making me do like this creature card Drool.  

I'd really love to make the art on these cards in the game - so whimsical (my word of the week).

I've literally never even heard of this game, so it's definitely under-appreciated haha! Looking at reviews and stuff it looks right up my alley too!

Come on, we all know Viewtiful Joe is a GameCube game before it's a PS2 game :)

Kidding aside, I'm glad you're finally playing it! It's a damn great game, hard as hell though. The follow-on games aren't of the same caliber, but 2 is at least passable.

Not sure how underappreciated they were, but the Shin Megami Tensei: Devil Summoner games were pretty damn good. At the very least, they were overshadowed by the Persona games. They incorporate some Tales-like gameplay with the staples of the SMT series, including Demon negotiation and capture. I'd love to see Atlus revisit the series this gen.

It was Viewtiful Joe on Gamecube that made me think of that as my cartoon game system.

I actually did not know that. I just always associated Clover with PS2 for some reason.

 Yep, it's darn hard, especially on adult mode. It's so satisfying though that I can't fault it for that though!

 Devil Summoner is a game I need to get around to. I remember trying to track it down after seeing it in a Playstation magazing but never being able to find it in my country. I was always really drawn to it's aesthetic as a kid though.

Two games come to mind: Beatmania and Taiko Drum Master. I don't know if both these music rhythm games came out the same time as Guitar Hero but for me there wasn't much hype to them and I thought they were a lot of fun. Both were based off of arcade games and had special controllers (Beatmania had a board that was similar to DJ Hero but had buttons, and Taiko Drum Master was the drum head with drum sticks) I own and enjoy both games and it would be nice to see some sort of return of both to the consoles. Oh I know that Taiko Drum Master is still alive and kicking on handhelds but I want to play those games with the special controllers.

A game I really didn't play but I thought was ahead of its time was Final Fantasy XI, not for the game itself but for the fact that it came with a 40GB hard drive that I currently use as a big memory card. I have all my game saves from Playstation 1 and PS2 on there and as a bonus 2K Sports games would install their save files on there automatically. I also believe a handful of other games would do the same. 

Hooray for Taiko Drum Master!

Champions of Norrath and Return the Arms come to mind. Now the games got pretty good reviews however half the time I talked about them people would ask "What game is that?" I feel like they werent has popular or well known and in my opinion should have been. Me and my sister played them a lot and never got bored.

Champions of Norrath was actually pretty popular in my hometown. I remember a ton of my friends being kind of into it, and Iplayed the demo to death - though I never got the full game.

 Never heard of the other one though.

Return to arms was the sequel to Champions of Norrath. It was not popular where I lived sadly.

Wow. It can't have done well then. I didn't even know it had a follow up, let alone what it was called! I remember really liking the original though.

Here's some:

Okami

Psychonauts

Klonoa 2: Lunatea's Veil

Taiko Drum Master

Mad Maestro

Tales of Legendia

Katamari Damacy

The Klonoa games were my childhood!

 Katamari Damacy has one of my all time favourite videon game soundtracks! 

 Okami's 15 minute unskippable "cutscene" with irritating voices can go find a cliff and jump from it, but otherwise great game.

 Never played a Tales game, though I hear great things, and I haven't heard of the others at all!

Monster Hunter (originally launced on PS2)
Killer 7 (originally launched on Gamecube, but still good game)

Shadow or Rome (I really loved this game. I loved the location and story)

Gungrave (Generic shooter with action horror theme, but I liked it)

Valkyrie Profile 2 ( Very odd mix of 2D exploration with 3D combat) 

Dragon Quest VIII, hands down. It is a magnificent RPG set in a wonderfully rendered world.

Viewtiful Joe is a great game as well, but I like the Gamecube version better.

I want to say Wild Arms 3.  Same with the original Wild Arms, with high caliber games in the Final Fantasy series really stealing their thunder.