Recommend a game... win a prize 2 :D

Minecraft: The game that's forever an alpha.
They only started calling it "complete" so they could get more money without doing more work. I like it, though.

If you're looking for a scare, this is the game for you: http://www.indiedb.com/games/paranormal

END OF NATIONS

Kerbal Space Program or Starfarer both really worth your time

Terraira

Shootmania?

Legend of Grimrock. Really great :3

This looks fun: King Arthur's Gold
Watch the video on the main page and check the about page for more info. Looks kind of like Terraria war :)

RaiderZ or C9

Kerbal Space Program, Ravaged, RaiderZ, DayZ... These are some great beta games currently

SCP Containment Breach and Paranormal

Ravaged

Ravaged Beta

Bloody Trapland

its like super meat boy but with coop :)

STALKER Online currently in beta.

http://stalker-online.co/?lang=en

It is still a bit rough (the english client), but great fun to adventure with fellow stalkers. If you decide to start up, let me know I can hook you up with some gear =)

Delver Alpha

CS GO BETA

Ghost Recon Online :)

Project Zomboid, pretty cool

Overgrowth. The developers made it while on LSD, should be interesting.

Awesomenauts pc beta

Slender!!!

Planetside 2 looks orgasmic! Too bad that it's a closed beta, cause the game looks sweeeeeeeet

Deus Ex :3