Where to start...
PC:
Half-Life 2: Episode 2.
Half-Life 2: Deathmatch.
Battlefield Heroes.
Trackmania Nations Forever.
Soldiers: Heroes of WW2.
Painkiller: Black Edition.
The Guild Gold.
Grand Chase.
Guild Wars.
Wizard101.
Florensia.
Stronghold.
Second Sight.
XBOX360:
Halo 3.
Gears of War.
Elders Scrolls 4: Oblivion.
Dark Messiah of Might and Magic.
Dead or Alive 4.
The Orange Box.
Army of Two.
GTA 4.
PSP:
Resistance: Retribution.

Battlefield Heroes, The Guild, Rush For Berlin, Combat Mission Shock Force.

I played Lords of Magic and had my ass handed to me ...

Played/currently playing: Rise of Nations: Gold Edition.
Finished: Peggle: WoW Edition, Neighours from Hell 1 and 2.
Also, got Fallout 3 from a friend, and played it a little. Its nice, but until somebody fixes the bugs, I'll stay away from the game.
EDIT: Oh, forgot that I also finished Flatout.

How is The Club? I've been curious.
Me, I've been playing pretty much only Lost Planet Colonies on PC. Bit of Street Fighter IV (er, "discounted" version as my proper copy is two weeks late). I may give up on LPC soon -- it's driving me mad. Will probably be playing Devil May Cry 4 a lot next week. Yep, on a Capcom binge..

Red Faction: Guerrilla
Favorite game on the PS3 by far.

360: Gears Of War 2, The Secret Of Monkey Island Special Edition, 'Splosion Man (demo, also boring)
PC: Dawn Of War 2 (lots), Planescape Torment

Think NASCAR and any FPS you can think of, but it more focused on quick kills.

Well, it's monday morning and I was mostly watching season 7 of the X-files yesterday...
PC: Evil Genius. (I should finish it off today or tomorrow)
Last week, was more EG, some Earth 2150, Fantastic Pinball and a bit of Mahjong Titans while waiting for people.

COGS, Flatout and a microscopic amount of the Sims 3. I did pop onto Arx Fatalis for a bit, but I've forgotten all the controls and I got murdered pretty quickly.
Far Crizzle has been a constant source of anger as I can't even get past the first watchtower. I've literally tried everything and I just don't 'get' it. Ah well.

Lying in the bushes and long range shooting are your friend there. The M4 has a decent level of zoom and you can pop single shots into the guard up there without becoming exposed

It's an arcade/shooter game focused on achiving high punctuations. You receive more points for headshoots, long range kills, last bullet kills, killing a lot of enemies in a row... It's not very deep, but is pretty enjoyable.

Yep I gave that ago, but only once, I better try again. The first time I tried, one single shot alerted the whole camp, the alarm was hit, a helicopter dropped in and someone in one of the watchtowers went mental. Even though I moved, those sukkas just followed me. I was totally hidden when I made the shot, and a good distance away. *sigh*

You'll get past it, you just have to make it halfway through the game and then you can be really pissed off at how shit it gets with the non-human enemies
Oh I've thought of another PC game I, and a number of other GOGgers have been playing, 3D Ultra Minigolf Adventures (tee hee)

GOGers and STEAMers :o