-Arx Fatalis - A first-person view action-RPG that mostly takes place in underground caverns and catacombs where humanity and fantasy creatures have taken refuge after a disaster on the surface. Very reminiscent of games like Ultima: Underworld and King's Field (unfortunately, the soundtrack is SEVERELY lacking, unlike King's Field).
-Baldur's Gate: Dark Alliance 1 & 2 - Most people have heard of these games, and it's for good reasons. If you like games like Diablo, Dungeon Siege, and Champions of Norrath; then you'll absolutely adore these games.
-The Chronicles of Riddick: Escape From Butcher Bay - One of the best looking games on the system. It's a FPS by definition, but there's a whole lot more going on than just shooting. Lots of sneaking, melee combat, and exploration too.
-Dungeons & Dragons: Heroes - Great hack-n-slash action-RPG like Baldur's Gate: Dark Alliance or Champions of Norrath. If you're into those types of games, this one will suck you right in and give you that addictive loot-finding gameplay.
-The Elder Scrolls III: Morrowind - The reason I personally bought an Xbox. It's an open-end, open-world action-RPG. And the world if freaking HUMONGOUS and highly detailed at the same time. When it released, there really was nothing else like it.
-Halo 1 & 2 - The reason many people bought an Xbox. Fantastic sci-fi flavored first-person shooters with a whole lot of shine and polish. And one of the most memorable soundtracks of all-time. Great single-player campaigns with fantastic stories, and a fantastic multiplayer section that many modern shooters owe a deal of thanks for.
-The Incredible Hulk: Ultimate Destruction - This is what a Hulk game always should have been. You actually feel like the rampaging, destructive, and out-of-control Hulk you remember from the comics. Highly-destructible environments. Upgradable powers. And a VERY fun "leap long distances" game-mechanic.
-Jade Empire - A fantastic and unique action-RPG that focuses on Ancient China and martial arts techniques. Choice-based storyline, as well, that actually affects the ending of the game. Great experience that anyone with an Xbox really needs to play.
-Marvel Ultimate Alliance - This game borrows the gameplay from games like Baldur's Gate: Dark Alliance and Champions of Norrath. It improves upon it. And it sets it in the Marvel Universe with a bevy of Marvel characters to choose from, as well as more to unlock. So much fan-service provided for the comic fans, here, too.
-MechAssault 1 & 2 - Do you like giant robots? Do you like to blow stuff up? Do you like destructible environments? Then these are the games you are looking for! Just a ton of fun to romp through these and destroy everything.
-Ninja Gaiden - Absolutely gorgeous 3D action-platformer based off the old-school series of Ninja Gaiden games. Tough-as-nails gameplay, though. However, the difficulty is based purely on your skill (or lack of). The controls are absolutely precise, which makes it that much more fun to play. Also, VERY bloody.
-Pac-Man World 2 - Probably the single most underrated 3D platformer of that generation. It's seriously a great, fun game with well-designed platforming levels. And it's actually a platformer, rather than a collect-a-thon like so many other so-called platformers are from that era.
-Spider-Man: The Movie - Everyone loves to talk about Spider-Man 2, with it's open-world sandbox gameplay. But as a result, everyone overlooks this gem of a game. Yes, it's level-by-level, but why is that a bad thing? Spot-on, fluid controls and a fantastic web-slinging mechanic make this game so satisfying to play. And then after you beat it, you get the freaking coolest unlockable I have ever seen after beating a game (well, except for an entire 2nd quest in the original Legend of Zelda): You get to play as The Green Goblin complete with his own unique powers and move-set, and you get full use of the Goblin Glider and his weaponry!
-Spider-Man 2 - This one is good, as well. Like I said above, open-world sandbox gameplay. You can choose to strictly follow the story events only, or you can just web-sling around New York City (which is a blast to do, BTW), and stop random crimes.
-Star Wars: Battlefront 1 & 2 - These games are complete chaos set in the Star Wars universe, and I love it. I'm not even a huge Star Wars fan, but these games are fun nonetheless. You are in control of a side in battles that actually took place in the Star Wars movies. However, you are only in control of 1 character at a time. That character can also commandeer any vehicle or stationary weapon you see. When that character dies, you get another one. And you battle until you win, or until your side's forces are depleted.
-Tecmo Arcade Classics - An exclusive classic game collection to the Xbox. Definetly worth the small price it goes for if you're into the mid-to-late 80s arcade scene. Tons of other fantastic collections out there for the Xbox too, but they're also on other systems (Capcom Classics Collection 1 & 2, Mega Man Anniversary Collection, Street Fighter Anniversary Collection, Sonic Mega Collection Plus, Atari Anthology, etc.)
BTW, MetalJesusRocks...um, rocks!
