Your First Steam Game

Day of Defeat Source I Guess

Free Portal.

Half Life 2: Death Match

Saints Row The Third

counter strike GMOD bundle

orange bundle or whatever it was called

It was the ATI promo. Wow that were a long time ago

CSS.

HL2.

Portal 2 for xbox though that doesn't count. It was really Team fortress 2 and Terraria

I think a friend gifted me Portal. It was a while ago! I had bought Half Life 1 Anthology (on CD), but hadn't realized I could activate it on Steam until about a year ago.

mount blade warband

portal 2 CD

Fallout New Vegas

Red Orchestra. I remember hating that I had to create a steam account and have steam on my computer.

TF2, about 2 years ago. Then it was Portal.

Magicka

Terraria. I won a Sequence raffle on a different site, and I'm not sure why, either I really couldn't or I didn't think I could accept it, but I thought I had to buy a game, so I bought Terraria which was only 2.5$(2011-12 Winter Sale) and looked interesting, so I asked my friend to lend me the money since I didn't have my Visa yet.
Tl;DR Terraria, Steam Winter Sale this year.

quake 3

Modern Warfare 2

spiral knights oh yeah

My first game was TF2. TF2 brought me on steam, but I don't played it almost a year. I stopped playing TF2 since i purchased some games. And first purchased game was awesome game called Just Cause 2! :)

Counter-Strike: Source + Garry's Mod pack

CSS/DoDS/HL2DM pack.