This year i finished few games that i will remember for longer time:
Theatre of War
Fear 2
Grid - career two times and I'm playing the multi since then
Far Cry 2
World in Conflict & Soviet Assault (awasome game, landed on my list of 5 best strategies ever pleyed next to titans like Heroes 3, Homeworld, Company of Heroes, Ground Control)
Patapon & Patapon 2 (PSP)
Also i finsihed Bioshock & Company of heroes second time :-)

Just finish The Legend of Zelda : Ocarina of Time for the first time

List updated. Check your name for any mistakes (misspelled names, missed a game etc.)
fun fact:
101 people are on the list. almost 1600 words. Not sure whether there is a way to find out how many games (it might be problematic since the naming is not very consistent and games are grouped together, for example: Beyond Good and evil or BG&E, Broken sword 1-3 or HL1&2) I can do this by hand but in January; :)
@apoc:
you do like Zelda games don't you :)
which quake and what expansions?
i need more info to put you on the list

Stonekeep
Was amusing, but somewhat tedious towards the ending.
Lionheart: Legacy of the Crusader
Extremely tedious, interesting setting.

1st Quake plus Scourge of Armagon and Dissolution of Eternity

finished for the first time:
Prototype
Zeno Clash
Dark Sector
HL: Blue Shift
Defense Grid: The Awakening
F.E.A.R. 2
Cryson Physics
World of Goo
Red Alert 3
Sam & Max season 1
American McGee's Grimm
finished for at least the second time:
Assassin's Creed
Duke 3D
Bioshock
didn't yet finish, but in the works:
Mirror's Edge
Prince of Persia
Cryostasis

Half-Life
Unreal Tournament
Unreal
Zombie Shooter
Star Wars Battlefront
Geometry Wars Galaxies (Wii and DS)
Jet Storm Modern Dogfights (known in North America as Jetfighter 2015)
Terrorist Takedown
TimeShift
Serious Sam 2

Quite a few I'm proud of, mostly a time issue for me:
1. Assassins Creed
2. COD: World at War
3. Quantum of Solace
4. Mirror's Edge
5. Dead Space
6. Kane and Lynch
7. Crysis and Crysis: Warhead
Currently making my way through Far Cry 2 and The Witcher

Well, The Lich King took most of my time. Besides that game:
-> Fallout 3
-> Sam & Max S1 & S2
-> Jade Empire
-> Defense Grid
-> World of Goo
-> Dungeon Siege
-> Empire: Total War (as far as you can finish it)
-> Anno 1701
-> Beyond Good & Evil
-> Quite a bit of Team Fortress 2
-> Stronghold. Except for the last three or so missions.
But even if I add all the hours I spent on these games I won't have as much as I spent on TLK.

so far I have only finished
Rainbow Six vegas
Rainbow Six vegas 2
peggle deluxe
gta : chinatown wars
fable 2
Need to get more classics off gog!

Prototype

Hell yes, finally finished inFamous. May replay that, I sort of just skedaddled through the whole game without looking under the metaphorical rocks. Actually, I'm booting it up right now.
Oh, and finished Manhattan Project. Great fun, worth the $5.99.

Since I last checked in : RoTT, 1nsane, and Septerra Core (as long as several games) are finished.
Not as many as I hoped, but the topic is active so I'll mention them now.

Tomb Raider Underworld

Bioshock
Red Alert 3
Unreal
Unreal Tournament
Unreal 2
Unreal Tournament 2004
Postal 2
Fallout
Fallout 2
Sacrifice
X-Men Legends
inFamous