Where do you guys get all these Steam gifts?!?!

Steam.

Mostly bundles, sales, Steam.

Usually from Bundles like: Humble bundle, Indie royale, indie gala, etc... lots of games for a couple of dollars
you might want to check here:
http://www.reddit.com/r/GameDeals/
and here
http://forums.steampowered.com/forums/showthread.php?t=2981458

Cheap bundles, cheap sales, trading, etc.

Gifts? From the steam store. Many giveaways are keys though.

From the grocery store.

Umm... checks empty wallet, I don't know.

I work on my uncle's gift farm, I sometimes get to take one home

They just spring out of holes in the ground!

Steam what? Gifts? The fuck are gifts?

I randomly find them in my inventory after idling in Fortix.

From Russians

By repenting for our sins to Overlord Gaben

we buy them and then give them away here. Well, barring a few people who get them from devs

Some people have kinda a lot of moneyz :P