Top 5 PC games of this generation.   Just vote for your top 5.  Scoring works like this. This generation includes games released from November 22nd 2005 to present.

1. 5 points
2. 4 points
3. 3 points
4. 2 points
5. 1 Point

My Top 5:

1. Portal 2
2. Skyrim
3. Far Cry 3
4. The Witcher 2
5. Portal

1: Minecraft

2: Guild Wars 2

3: Shogun 2: Total War

4: Empire: Total War

5: Skyrim

1: DOTA2
2: Starcraft2
3: Portal2
4: Trine 2
5: CS:GO

1. Portal 2
2. Left4Dead
3. Alan Wake
4. Mass Effect 
5. The Walking Dead

Playing Guild Wars 2 and Saints Row 3 i had lot of fun too. 

I'll only include games I actually played on the PC so no fallout 3 or Left 4 Dead =(.

I'm probably emphasising games I recently played way too much. But heck this is how I feel right now.

1. Heroes of Newerth
2. Elder Scrolls V: Skyrim
3. Dark Souls
4. FTL: Faster Than Light
5. The Walking Dead

1. Fallout 3

2. Minecraft

3. Starcraft 2

4. Civilization 5

5. X-COM: Enemy Unknown

1. Bioshock
2. Portal 2
3. X-Com: Enemy Unknown
4. Company of Heroes
5. Sins of a Solar Empire

1. Deus ex: human revolution
2. Supreme Commander
3. Dark Soul's
4. Fallout: New Vegas
5. Crysis Warhead

1. Portal 2
2. Mass Effect
3. VVVVV (I'm probably the only one who is going to mention this)
4. Left 4 Dead 2
5. Bioshock

1. Skyrim
2. Mass Effect 2
3. BioShock
4. Portal 2
5. Civilization V