The first game on steam?

Batman: Arkham Asylum

Wikipedia knows better, CS.16

Half life 2

First game on steam : Dota 2 Beta

First game on steam that not made by valve : Back to the Future: The Game

Half-Life ofc

Ragdoll Kung Fu for the 1st non-Valve game.

Mine was garry's mod (doesn't count cause it's a mod), but then I tried to play it and it needed a source game so I bought half-life 2: deathmatch :D
Magicka was the first game not made by Valve that I had on steam

L4D2 demo. It was the reason why I created my acc and installed Steam.

MW2 ^_^, was like month - two after launch

Installed disc it and its asked steam account , so I did ^_^

After that I searched in steam store and found an amazing pack , THE ORANGE BOX

Bought it and finished half life 2 in 2 days , than played episodes :)

was a pack with CSS, Dod and HL2 deathmatch

Orange box games ;*

Cod mw 3

My First Game on Steam is Counter Strike Source + Day of Defeat Source in a Pack with a New Headset x)
This March 2009 ^^ have Creating my Account and Played CSS and DODS with my Friends

I love how everyone is completely missing the point. Go figure. It was Counter Strike for both things, which wasn't exactly Valve by the time, but Serria.

Im not sure its either Half Life 3 or Mirrors Edge 2

Left 4 Dead.

CS1.6 + Zero/Deleted scenes
Friend gave me as gift.

Terraria.

Gift Magicka from a friend

I clearly remember it was skyrim

Race 07

it was Portal, I got it for free on a special offer, and left it there, and when Skyrim came out it was the first game I bought original in a very long time, I got hooked to that game till Christmas when I discovered the christmas sales.

CS 1.6

Counter-Strike Anthology 1

Left 4 Dead