Keep in mind that this list is games I've played.  It is not my comprehensive list of what everyone and the world should view as the top games of the last decade - this is only my personal favorites. 
 

50.  Titan Quest (PC) - Titan Quest took the Diablo 2 formula, upgraded it with better graphics, and then promptly dropped off the radar.  Sadly, support for this game only lasted through one expansion pack. 
 
49. Psychonauts (various platforms) - Tim Schafer crafted a gem of an adventure/platformer with Psychonauts.  Some cleverly designed levels, a great sense of humor, and a fantastic art style helped cement this game's quality. 
 
48. Pirates! Live the Life (various) - This is a great example of how you can take a classic game and make it relevant in today's gaming marketplace without sacrificing any of the original gameplay.  Pirates is thoroughly addictive and loads of fun. 
 
47.  Half-Life 2 (PC) - Great shooter with an interesting setting and environment. 
 
46.  Final Fantasy 12 (PS2) - I greatly enjoyed the combat mechanics of this deep RPG, but I wish the characters and story had been slightly more interesting.  Still a classic RPG in its own right. 
 
45. Animal Crossing (Gamecube) - I think this game truly marked a revolution in Nintendo's approach to gaming.  It would certainly feature some original gaming, and was highly addictive. 
 
46.  Borderlands (various) - Simply a fantastic first game in what will hopefully be a long-running IP.  Great art style, fantastic shooter gameplay crossed with RPG elements, and a trippy sense of humor that I absolutely adore. 
 
44. Ratchet and Clank Future: Tools of Destruction (PS3) - Bright, colorful gameplay, an insane selection of weapons, and just a joy to play.  I really enjoy this one, and hope to play its sequel and predecessors in short order. 
 
43.  Legend of Zelda: Twilight Princess (Wii) - I enjoyed Wind Waker, but I thought TP was a bit more polished and fun to play.  Although I'm not a huge fan of the Wii controls, the game is also available on Gamecube and can be played with a Gamecube controller, making it a moot point. 
 
42.  Modern Warfare/Modern Warfare 2 - These games would have placed a lot higher on this list, were my vision not so crappy.  As it is, I can enjoy the single player campaign, but have never been able to get into the multiplayer. 
 
41.  Halo: Combat Evolved (Xbox) - A groundbreaking game for Microsoft and Bungie, and a fantastic game still today, Halo has become a benchmark of gaming. 
 
40.  Star Wars: Knights of the Old Republic (Xbox) - A stunning RPG from Bioware, who have gone on to become one of the top names in RPG's today.  Knights of the Old Republic manages to surpass its sequel on this list due to its slightly better ending and more interesting characters. 
 
39.  Suikoden III (PS2) - An often overlooked RPG from one of the best series of games out there, Suikoden III did a lot of innovative things with the series, including three main characters, new cartoonish graphics, and.... ducks? 
 
38.  Lord of the Rings Online - Oh, LOTRO, how many hours have you sucked out of my life?  This well-designed MMORPG has some gorgeous graphics, an easy pick-up-and-play attitude (for an MMORPG, that is), and a keen eye to Tolkien lore. 
 
37.  Rogue Galaxy - It was hard to choose between Dark Cloud 2 and Rogue Galaxy, as they share a great many similarities, but in the end, the massive Rogue Galaxy wins out.  The charming visual design, the endless hours of gameplay, and the sheer amount of sidequests and time-sucking activities make this one of those "if you were on a desert island" games. 
 
36.  Rock Band (various) - Talk about a game changer.  Guitar Hero was great - Rock Band was amazing.  Either game could easily make this list, but for my money, Rock Band is where it's at. 
 
35.  Disgaea 3 - Any of the Disgaea games could go here, but as Disgaea 3 is the newest and most complete addition to the series, it's got my vote.  This game has sucked hundreds of hours of my time, and I keep coming back for more. 
 
34.  Metal Gear Solid 4: Guns of the Patriots (PS3) - Again, another series where just about any entry will do, but MGS4 is an amazing experience both cinematically and gameplay-wise.  If it wasn't for the horrible "sneak and follow the civilian" mission, this would be much, much higher. 
 
33.  Final Fantasy IX - Another fine entry in the FF series, this one had a classic throwback feel to it and a whole hell of a lot of charm.  It was one of the finest RPG's for the PS1. 
 
32.  Tekken Tag Tournament - I don't think I've sunk more hours into a fighting game series than the Tekken ones, and Tekken Tag Tournament was certainly a high point in the series.  Later iterations are just fine, but this one had an excellent cast, rock solid gameplay, and gave my friends and I hours of fun. 
 
31.  Tiger Woods 10 (various) - One of the most consistently entertaining series of sports games out there, Tiger Woods 10 proves to be the best in the series with its revamped putting controls, excellent motion controls on the Wii, and some fun new additions. 
 
30.  Wii Sports (Wii) - Games are meant to be fun, and as such, Nintendo knew they had a smash hit on their hands, because Wii Sports is a freakin' blast.  Bowling with friends and family never gets boring, and there's nothing quite like taking out some frustration in boxing or baseball. 
 
29.  Twisted Metal Black (PS2) - I love me some Twisted Metal, and there's no game in the series that stands up to its biggest, meanest edition to date.  Twisted Metal Black is wicked, damn good fun, and the characters are the best to date.  Sweet Tooth and Axel, come back to us!
 
28.  Grand Theft Auto San Andreas - San Andreas nailed the GTA best - it had all the classic open-world elements, an insane cast, and a hell of a lot more to do in its world than GTA IV.  It would surprisingly be passed by a rival in... 
 
27.  Saint's Row 2 - Saint's Row 2 took everything that made the GTA series so amazing, threw on twice the craziness, cleaned up its gameplay, and added a boatload of mini-games.  This is open-world perfection.  Plus, you can customize cars, which a certain modern competitor can't boast. 
 
26.  Forza 3 - Forza 3 is quite simply the king of simulation style racers at the moment.  It's a blast to play, even for a legally blind guy like myself, and its selection of cars is admirable.  If only it had more muscle cars... maybe in the future, huh? 
 
25.  Silent Storm - SS takes the established Jagged Alliance formula, updates it with some nicer graphics and destructible environments, and lets the player loose.  If it had the charming characters and interactions of Jagged Alliance 2, this game would be at the very top of this list. 
 
24. Bioshock - One of the best shooters I've ever played, and an absolute treat from start to finish.  This is a game I'll be revisiting years from now. 
 
23.  Shenmue 2 - The saddest part about Shenmue 2 is that it doesn't end on a proper note, and we may never get a sequel.  That being said, the gameplay is still ridiculously fun, and it holds up impressively well. 
 
22.  Portal - Without question, the most important puzzle game release of the decade, and a damn fine game on its own merits.  I still haven't figured out a disturbing amount of its puzzles on my own.  Yes, I know, the shame, it mocks me, it mocks me... 
 
21.  Final Fantasy Tacics A2 - Final Fantasy Tactics might rip a page or three straight from its predecessors, but that doesn't make it any less entertaining or fantastic in every possible way.  This is strategy gaming 101, ladies and gents, and listen up, because teacher's talking. 
 
20.  Super Smash Brothers Wii - With a huge roster, a surprising amount of depth, and a meaty story to play through, SSB is one heck of a fighter. 
 
19.  Civilization Revolution - What an utterly astounding mix of intelligent tactical gameplay and pick-up-and-play gameplay!  This is a rare gem of a game, one that I believe can be enjoyed pretty universally. 
 
18.  Elder Scrolls III: Morrowind - Morrowind was simply a stunning game, one I was transfixed by for months on end.  Stepping out of the ship for the first time, I knew I was in for something special.  Years later, I still hold firm to that belief.  This is a superb RPG, and not to be missed. 
 
17.  Sam and Max (new episodes) - With the new Sam and Max episodes, we old PC gamers saw the rebirth of a genre many of us thought dead.  This is a straight-up infusion of gaming goodness, with classic adventure elements and some fantastic writing. 
 
16.  Left 4 Dead 2 - This is a prime example of how gaming has shifted away from single-player to multiplayer with astounding results.  This is also, unfortunately, a game I can't play alone.  Brrrrr. 
 
15.  SSX 3 - OK, I had a hell of a hard time deciding between Tricky and 3 to put in this slot ("That's what she said,"  Thanks, The Office).  But SSX 3's huge mountains, excellent soundtrack, and superb gameplay just barely eked out a win.  Consider buying both, as the crazy characters from Tricky are definitely worth a look. 
 
14.  Tony Hawk Pro Skater 2 - Although by now the series has become stale and redundant, there was a time with THPS was amazing, and this is definitely where the series got its true start.   I'd say Undergroung 1 & 2 were probably the best of the series, but this one deserves the nod for its groundbreaking gameplay and fun.
 
13.   WWF Smackdown vs. Raw 2010 - It's hard to pick a single S v. R game for this list, but I'd say the ability to download created wrestlers and content edges out Here Comes the Pain.  This is an amazing series of games that, while it definitely needs a serious tune-up, has become a staple at my house. 
 
12.  Super Paper Mario - This is a superb blend between classic gameplay and modern inventiveness, with a dash of humor and some light RPG elements.  I adore this game, and frequently come back to it. 
 
11.  Valkyria Chronicles - Tought as nails, but the gameplay is addictive and rewarding.  The plot is intriguing, as are the characters. 
 
10.  Super Mario Galaxy - No one does platforming like Nintendo, and Mario Galaxy is the best of the decade.  I
 
9.  The Witcher - Straight out of the box, The Witcher is pretty buggy and flawed, but once you've patched it, settle into a chair for the next few days.  You won't be going anywhere.  The gameplay is incredibly fun, the story is fantastic, and the dialogue is without peer.  This is an incredible PC RPG. 
 
8.  Halo 3 - I can't compete in Halo.  It's sad, but true.  That doesn't stop this from being my all-time favorite shooter, a game in a class all by itself.  Halo's not technically complicated, but the gameplay is fast, fun, and addictive.  And there's still not any game on the market that can compete with its matchmaking capabilities. 
 
7.  Diablo 2 - One of the OG's, Diablo 2 originated a lot of hack-and-slash gameplay elements, and it's still yet to be rivaled in that department. 
 
6.  Elder Scrolls IV: Oblivion - Oblivion took everything that was amazing in Morrowind, made it more accessible, and ran with the ball in every conceivable way.  It is a fantastic game from start to finish. 
 
5.  Arcanum - Perhaps the last great hurrah of the eagle-eye turn based RPG's, Arcanum was a fantastic game that followed in the tradition of games like Fallout 2.  Not surprising, since it was made by the same developers.  Arcanum still plays well today, especially with the homemade patches out there.  It's not for everyone, but the steampunk envornment and classic dialogue makes this a no-brainer for an RPG nut like myself.
 
4.  Suikoden 5 - This was a throwback in the series, a cry to fans of the original two in the series, and it worked on every conceivable level.  Suikoden 5 has a fantastic story, an army of likable characters, and enough side-quests to keep most gamers going for dozens of hours beyond just the main story. 
 
3.  Mario Kart Wii - These last three took hours of deliberation (and a few beers) to help sort out which belonged where.  Any single one of them could be in the top slot, but we start the last three with Mario Kart Wii.  Mario Kart Wii is classic gaming at its very, very best.   The traditional colorful cast of characters is mated with the same great gameplay of its predecessors with the additional spot-on Wii controls.  This is a riot to play with friends, online, or solo. 
 
2.  Fallout 3 - My apprehension at the thought of a new Fallout game was quickly allieved within the first ten minutes of playing it.  Fallout 3 is one of the best games ever released - period.  With a lengthier main quest, it could have nabbed the number one position, but as it is, Fallout 3 is well worthy of all the praise I've heaped on it since its release. 
 
1.  Final Fantasy X - This is it, the big kahuna of the 2000's.  Final Fantasy X was the reason I purchased a PS2 when it was released, and it's still the best game on that system.  I adore every crazy minute of this game, and I still think it's the pinnacle of RPG gaming, turn-based or otherwise, to date as well as one of the finest games ever created.
 
Whew.  That does it for this week, folks.  I'll give you all a full update next week, including my most recent 360 woes as well as some classic PS1 gaming on the PS3. 
 
In the meantime, here's your questions of the week.  Yes, you get two this week.  First, what are your favorite Christmas (or holiday) traditions?  Second, what are your top three, five, or ten picks for games of the decade?