All the others

In no particular order.

Spore

This game only just missed out.  I still play it a bit, but I dont actually like the civilisation stage, it is pretty basic, and beyond easy level, is really hard.  So I get frustrated and goto another game.  Also at the space level, it gets very crowded very quickly and this also detracts from the game for me, so I have a lot of planets at civilisation stage and My space stage games dont have all the bonuses you get from playing all the way.

Medieval

I got this on special and it was the precursor to Medieval 2.

Flight Gear

My flight sim of choice as it is available on Linux.  It is really good and has great realism for a free game.  I highly recommend it.  I have slowed a bit on playing as the joystick is getting a bit old, but I suspect I'll be palying more in the new decade when I get the new joystick, or maybe even a yoke.

Assassins Creed

This is quite a good game, and I get the apeal.  I bought it second hand for the PS3, but found after my third city, that it is all the same and got bored with it.  I will most likely try Assassins Creed 2, but when I can get it for around $30 I think.

World of Warcraft

I played the RTS Warcraft a lot in the nineties, but it took a bit of time before I tried WoW.  It is a good MMORPG but when you pass level 20, you just do all the same things again, just in a different region.  This I found boring so I stopped playing.

Sim City 4

Another game that almost made it to the list.  I still play this a bit, but I only install it now on Linux and play it under Cedega.  The newer PC with XP 3 seems to really bog this game down for some reason, and not many people play, and it is no longer supported.

Trainz

Good simulator and my version has the paint shed and all.  Runs really well on Linux.

Never Winter Nights

the RPG I went for after Ultima IX and Ultima online.  Good story line, but got stuck in a region and lost interest.  There was a native Linux client, another reason why I got it.  Would still recommend it though, but not many people in the online worlds any more as they have gone to NWN2.

Never Winter Nights 2

Apparently works on Linux in Cedega, but I have never been able to get it to work, so I ahve not played this much.  I loaded onto windows to check it out, but it was bought for my Linux system, I might get it running one day.

Sing Star

A lot of fun this game.  Not a huge favorite, but I do like to paly very now and then with Carmel.  Paige is not much fun, because she always wins except once, I think it was "Blue Monday" and that was because she did not know the song.

Jak and Daxter

Platform game for the PS2.  Good game, but you will probably need a walk through, I did.

Dakar 2

One of the most difficult racing game I have ever owned, hated it so much I gave it away, and the guy I gave it to hated it so much, he gave it away.

The Urbz

A console version of the Sims.  Pretty good, but does look a tad dated now.

Dragon Age

Just new in the last decade.  Really good, but will most likely be a favorite in the next decade.  You will have to wait ten years for the review.

Ultima IX

Although I played this a lot this decade, I still class it from the nineties, and it was greatly over shadowed by Oblivion.

Ultima Online

Stopped playing this around 2002 as I could not get to play regularly.  I would still class this as the best MMORPG ever.  Graphically nothing like Everquest or WoW but for game play, out does them by a long shot, no other game like it unfortunately.  I might go back to it one day.

Guild Wars

Great game, but the disaster ruins the great scenery you experience at the start.  The online play is good and it is well structured.  I might load it onto Linux one day and play again.

Black and White 2

Good game, but I did not like the lack of choice when you start to play.  Again, works well on Linux, and I keep going back to it every now and then.

Civilisation 3

Was a bit of a downer after 2, as it was just all the same with some better graphics, free civ was much better and still is.

Civilisation 4

This was a great improvment over 3, which I felt was a bit of a flop.  The religion system was a good addition and the graphics where fantastic.  Again, another game for Linux with Cedega.  My only criticism is the worlds are still too small.

Medieval Lords

Castles and seiging.  Great game with city building and a military slant.  The only poor thing about it, the worlds are too small. 
Does not give the feeling of epic like medieval does.

X2 The Threat

Commercial spce sim, pretty good and very well doen with good story, but the space is a bit small, the new version looks great and is available for Linux, so I might give that a go in the new decade.

Caesar 3

Good city building game.  Works on Linux with Cedega.

Caesar 4

Fab graphics, but need a good system to be playable.  Have not played it much to make a comment in all honesty.

Pharaoh

Another city builder game.  I still play it in Linux with Cedega.

Freelancer

Another space sim released by Microsoft Games.  It was complete waste of money.  No joystick support at all.  The flight model was crap, and when you let go of the button on the mouse, the ship would orientate itself to your target, and your whole pursuit would be out of wack.  The game model is good, but I do not recommend you waste good money on this game, steer very clear of it, and get Vega Strike instead.

The worst game I have ever played.

Star Trek. Away Team

Great game, but I just had better ones to play.

Settlers 4

I am a settlers fan and 4 was very good, wasted many late nights playing this one, just missed the list as well.

Settlers: Heritage of Kings

This is actually better played as a campaign.  I am eagerly awaiting the release of Settlers 7 later this month I think.

Darwinia

Good little game and cheap.  I got it because it has a native Linux version.  Good value and just a nice little time filler if you need one.

Crimson Skies

Another Microsoft Games game, but this one is quite good.  I played this online with the old Microsoft Force Feedback joystick.  A lot of fun and I think the first game I ever actually finished to the end.

Stronghold Deluxe

Castle siege game, graphically old, but it is a lot of fun, takes a lot of time though.  I love using the tebuchet to launch dead cows into the castle.

Train Simulator

Microsoft.  Runs in Linux on Cedega really well, but I like Trainz better when it comes to making your own layout.

Majesty

Little strategy game based on fantasy characters.  Good little game and there is a Linux version.

Empire Earth 2

Good graphics, but again, the worlds where too small.