Compatible Steam Game Stores

AMAZON

Also gamestop on various games.

greenmangaming

Your local retail shop would have a few steam redeemable stuff.

Nuuvem
As with the other stores mentioned, only some games are Steam-redeemable, though.

getgamesgo

They have a Steam section.

maybe it's easier to look for stores that doesn't have steamable games? i can think of origin and blizzard store

g2play.net
intkeys.com

It doesn't matter where it matter if the game is Steam Works

Greenmangaming (My personal favorite)

Impulse (Gamestop)

Getgamesgo (Usually old games, but sometimes they give really good offers)

Buygamecdkeys (No experience with them, got it in Google search)

Cdkeyhouse (Never bought anything from them, my friend uses it though)

allkeyshop.com

Shady, shady stores.

Great topic, thanks a LOT! I've only used Greenmangaming before.

The answer to all

I have been asking myself this in the last couple of weeks, so far I only have redeem some amazon games (only the one that say it)

Eh, most of these sites either have shady names... Kinda worried about them...

g2play