Portal 2 has a nice selection of regular story-driven rewards, along with ones for doing abstract actions in the campaign (such as finding certain Easter Eggs), as well as a nice helping of co-op Achievements/Trophies.
We’re going to bypass showing you the ones you’ll automatically earn as you finish the campaign or the co-op levels. You’ll earn these as you play anyways, so we’ll focus our attention on the ones you’ll find ‘off the beaten track’ as it where.
They’re organised in the order that you’ll come across them in the campaign or the co-op mode. We’ll also detail which chapter and chamber you need to be in to get it. Let’s get started!

Door Prize
Examine all the vitrified test chamber doors

20

Drop Box
Drop your co-op partner in goo while they are gesturing by removing the bridge under them

20

Final Transmission
Find the hidden signal in one of the Rat Man's dens

20

Four Ring Circus
Enter 4 different portals without touching the ground in co-op

25

Iron Grip
Never lose a cube in Chamber 6 of the Mass and Velocity co-op course

20

No Hard Feelings
Save a turret from redemption

10

Overclocker
Complete Test Chamber 10 in 70 seconds

30

Pit Boss
Show that pit who's boss

30

Portal Conservation Society
Complete Chamber 3 in the Hard-Light Surfaces co-op course using only 5 total portal placements

20

Preservation of Mass
Break the rules in Test Chamber 07

10

Friends List With Benefits
While playing co-op, hug 3 different people on your friends list

50

Pturretdactyl
Use an Aerial Faith Plate to launch a turret

5

Schrodinger's Catch
Catch a blue-painted box before it touches the ground

20

Smash TV
Break 11 test chamber monitors

10

Still Alieve
Complete Course 4 with neither you nor your co-op partner dying

15

Triple Crown
Solve 3 co-op chambers in the Mass and Velocity course in under 60 seconds each

15

Wake up Call
Survive the manual override

5

You Made Your Point
Refuse to solve the first test in Chapter 8

10

Good Listener
Take GLaDOS' escape advice

5

Scanned Alone
Stand in a defective turret detector

5

Ship Overboard
iscover the missing experiment

10

Portrait of a Lady
Find a hidden portrait

10