And no, I don't mean WoW or any other online MMORPG drug.

I've been out of the PC gaming scene for a heck of a time, with Half Life 2 being the last thing I played. Oh, and Gears of War on a severely underpowered PC.

Right now I've got a mid-end system with a quad core and a Radeon HD 5660.

So what would be a good action/adventure game to get?

 

Team Fortress 2

 

Starcraft 2

 

I've heard good things about Civilization V. Of course, that is neither action nor adventure.

 

Pretty much anything that is good on consoles is good on PC where multiplatform ability applies. If you want to talk PC exclusive, you might check out Alien Swarm, Civilization V, Arma II, STALKER, Starcraft 2, and Minecraft. Recettear is pretty good too, if you're in to Japanese RPG styles.

EDIT: Team Fortress 2 is also a good pick as Twist mentioned. The console version doesn't compare to the current state of the PC version.

 

Need For Speed Hot Pursuit comes out next week. The demo I played was awesome!

 

Not strictly a PC game...

 

As long as it's available on PC, it's all good  

 

In that case:
I'm not sure how well it ported to PC, but I was really happy with Darksiders as an action-adventure.

 

Minecraft
Rocket Knight
Batman: Arkham Asylum
Mass Effect 1 & 2
Noitu Love 1 & 2
Cave Story
La Mulana

 

Team Fortress 2, the finest hat simulator available today.

 

Team Fortress 2 has been less fun to me since they decided to monetize the game, but it is still very fun.

Left 4 Dead is also very fun, but you kinda need friends who also have the game so you can play together.

StarCraft 2 is great if you enjoyed the first one.

 

Name a better hat simulator.

 

This

 

Team Fortress 2 a million times over. Minecraft and Left 4 Dead 2 are pretty slick as well.

 

This man knows whats what about hat simulation.

 

Always wanted to play that Crysis. Looks so good.

 

I'll continue the recommendations for Team Fortress 2. You'll never need another multiplayer shooter again.

I'd also recommend Torchlight and Fallout 3. With regards to Fallout 3, check out fallout3nexus.com and start grabbing mods. Take your vanilla Fallout experience and turn it into something extraordinary.

 

I wouldn't go that far. Counterstrike Source and Day of Defeat Source are great, too.

 

Crysis
Far Cry 2
Gmod
Counter-Strike: Source
Half Life 2 Deathmatch
Halo Custom Edition
Left 4 Dead
Left 4 Dead 2
Team Fortress 1
Team Fortress 2
City of Heroes/City of Villians
Medieval II Total War
Star Wars Galactic Battlegrounds - Clone Campaigns
Star Wars Empire at War
Fable - The Lost Chapters (Because of all the mods)
Fallout 3 (Because of all the mods)
The Sims 2
The Sims 3
Battlefield 1942
Battlefield 2
Battlefield 2142
StarCraft Brood War
StarCraft 2
Multi Theft Auto: San Andreas
Doom 3
Mount & Blade: Warband
RollerCoaster Tycoon 3
ALL THE COMMAND AND CONQUER GAMES!!
And all the mods for all these games!

.... THE LIST GOES ON FOREVER... But thoses are my favorites.... =P