Gamecube games

[sidewinderl]

The GameCube is one of the most underrated systems, and it has plenty of quality games available.  It's especially good as a party console if you can get more controllers and players.  My personal GC collection is currently a bit over 160 games.

I'll list a few that haven't been said already, and I'll try to recommend one game per whatever category I come up with.

Fighting  

Soul Calibur II - this one was one of the system defining titles since the GC got the best version

RPG

Skies of Arcadia Legends - one of the greatest RPGs ever made

SRPG

Gladius - a great sleeper hit from Lucas Arts...if you like games like Fire Emblem, don't overlook this one

Sports

Sega Soccer Slam - the GC had some very good Mario themed sports games including Mario Strikers, but Sega's game was better

Star Wars

Rogue Squadron 2 - this is a must play for any Star Wars fan

Bond

Everything or Nothing - best single player Bond game of the generation...if you want multi, go with Agent Under Fire and Nightfire

Platforming

Billy Hatcher - an overlooked attempt by Sega to create a new mascot character

Shoot 'em Up

Ikaruga - considered to be one of the best ever and it's made by Treasure

Run and Gun

Alien Hominid - sorta like Metal Slug except you're an alien fighting off a swarm of FBI agents

Racing

F-Zero GX - another system defining title

Action-Adventure

Star Fox Adventures - another great looking game that obviously wasn't actually a Star Fox game

FPS

Timesplitters Future Perfect - 2 is also a great game, but Future Perfect exceeds it in every way, especially in story

Third Person Shooter

Metal Arms - definitely one of the genre defining games of the generation

Puzzle

Super Monkey Ball/Super Monkey Ball 2 - great Sega platform style puzzlers with great party side games

Horror

Eternal Darkness - another system defining game

Stealth

Metal Gear Solid: Twin Snakes - Metal Gear's equivalent of REmake

Party Fighting Game

Digimon Rumble Arena 2 - one of the pricey GC games unfortunately, but it's a great game if you like Digimon at all...I prefer it to Smash Melee

Third-Person Puzzle-Platformer Action-Adventure (now that's a mouthful)

Prince of Persia: The Sands of Time - one of the games that defined the generation and sold me on the GC in the first place (since it was the version I played)

Oddball

Ribbit King - it's golf with frogs and not much golf