My cousin has $20 on Steam, what should he get?

Bad Rats,Fortix,SotmC,Dinner Date,Petz.

If he's unsure, he should save it. Asking people who don't know him a bit is... a bit dim.

a prostitute,many people would give him sex for his glorious steam wallet.

148 hours in Infestation: Survivor Stories... h-how?

Whatever your cousin gets, make sure he gets 2 of them...1 for himself, and 1 for his helpful though potentially angry cousin.

Wait for halloween, maybe 10y anniversary sales.

yes please tell me what game i should get

Thanks again cousin

best choice would be to get some tf2keys from the community market with his wallet funds and trade them for the games he wants.
He can get much more this way than buying them from steam.

He should buy TF2 keys.

vvvvvv, super heaxagon

Any game with a Metascore above 90 should satisfy the average gamer.

the walking dead

Miasmata, best 15 dollars I've ever spent.

Amnesia: Machine For Pigs ^_^

Some patience to wait for whatever big sale come next.

anything that cost that much, games aren't meant to be played

If there's nothing he really wants to buy now, better wait until there is.

20 X Fortix

An Awesomenauts 3 pack. One for him one for you and one to giveaway

Counter-Strike: Source is still the best game you can buy for 20 bucks :)

Wait for a sale, your $20 will be magically converted into $80+
(Or a Daily, or Weekly... something that is 75-90% Off, or 4 or 5 things...)