I have $20 in Steam What should I buy?

Add 10 bucks buy Flamming Cliffs 3! It's on 40% sale today!

Can always store it in your inventory to trade later on if you don't like it.

Batman Arkham Asylum.

Wait for summer sales . Be patient :)

Definitely buy rust. Its still in alpha but if you like survivals, its really great. I have it and recommend it.

Starbound or Rogue Legacy

Super House Of Dead Ninjas. A SNES like frantic action game of constantly changing tower to go down through which rewards ever improving skill with some unlocks to making it easier each time you play. Smooth and fun that's just good fun all around.

Try the original game, basically a demo for Super, to get a feel. House of Dead Ninjas

The Stanley Parable is a must have!

A lot of Fortix.

Wait for Ikaruga to come out.

Nothing, save it until a game you want goes on sale. Instead, finish the Half Life series!

20 bad rats is the best deal!

The Walking Dead: Survival Instinct. :P

But only if you like stealth games. It does that well enough to be worth the $4 it is in Aus / NZ.

two copys of metal slug 3

Buy 1 game that cost 20$ or more that cost less. I dont get it how can someone tell you what game to buy...

As much Takedowns as you can get

Cards to craft badges.

Buy tf2 keys on the market
Trade those keys for games

You'll probably end up with 100$ worth of games with your initial 20$

20 fortix

Rent cheap bitches!

The Witcher!

Wait for the next big sale. You can get a ton of stuff really cheap.

http://store.steampowered.com/app/235210

THIS !!!!

Wait for the steam sale. NEVER buy/trade for any game unless it's on sale otherwise you'll turn into one of the little bitchy kids who whine "Wahhhh I bought the game 3 days before the summer sale and it's on sale! I was all the DLC for free!!!!!!". Once you see the key price drop back down to $2 then buy up a bunch of keys and trade them for games with the wonderful people of glorious mother Russia.

TF2 keys and use Steamtrade to get games.