What was your first game on steam? GA ended.

Modern Warfare 2. Got a key for it with my video card.

Bastion.

Unturned lol

Age Of Empires 2 HD my only game for a year

My first game on steam was the Bioshock trilogy, I bought the box at my local PC store like I did with all games before then, I forget if the game disks had me install steam, or if there was just a card inside saying that I had a free digital version and gave me a code, but either way, because of that game I learned about steams existence.

DOTA 2.

Mine was Fallout New Vegas: Ultimate

My first game was No More Room in Hell but it's free.
First game which I'm bought - Velvet Assassin

Dota 2.

My account page says it was the Humble Introversion Bundle, but in reality it was the free-to-play APB: Reloaded, which was my whole reason for getting Steam in the first place.

bioshock

Mine was Team Fortress 2 in 2010

Quake III Arena

Sniper Elite V2

Ace of Spades: Battle Builder. Looked fun back in the day.

CS 1.6, since steam was mandatory in order to play it. I didn't even know what steam was back then and why CS needs it.

That was back in 2005.

Half Life Platinum pack, 12'5 years ago...
Half Life (& DLCs) + Counter Strike + Day Of Defeat + Ricochet + Deathmatch Classic + Team Fortress Classic

Created this account for the sole purpose of Dota 2 then when I stopped playing for a while I let it be, eventually Paradox gave Europa Universalis 3 in their newsletter so I went back to Steam and ended up staying.

Ticket to Ride. I had the web/stand alone version and Days of Wonder gave everyone who bought that version free steam keys.

Um... cough Five Nights at Freddy's cough

Torchlight. :D

Borderlands 2 Game of the Year

Deus Ex: HR