Steam achievements - rewards?

Nope =) Only a warm fuzzy feeling in your chest =)

if you have the achievement showcase turned on, it will show "1 perfect game"

Gaben gives you Half-Life 3 closed beta

sometimes the e-peen grows bigger, but that's pretty much it

Yes

keep dreaming...

Half Life 3 AND you can hear gordon freeman's Voice

It's a nice idea, but while software like Steam Achievement Manager exists, the only reward you're ever likely to get will be a virtual todger extension.

Bragging rights? And if you have the achievement showcase it shows your number of completed games. Could also join a site like Astats or Metagamerscore so you can see how you rank with others as well.

No, they are too easy to exploit. Steam never took achievements seriously, and now they've missed out on an opportunity to truly compete with console equivalents.