Let's see if we can identify all of them! There are a bunch that look familiar but I can't quite put my finger on. I'll start off with some of the ones I instantly recognize:
(starting in the bottom left corner)
Clank from Ratchet and Clank
R2-D2 of Star Wars
Bad Robot from the Bad Robot logo
Noo Noo from Teletubies
Wall-E from Wall-E
Tom Servo from MST3K
Conky from Pee-Wee's Playhouse
Gir from Invader Zim
Rosie from The Jetsons
Marvin the Paranoid Android from The Hitchhikers Guide to the Galaxy
Alpha 5 from Power Rangers
...others, off the top of my head, are
Bender
Bill and Ted
Johnny 5
The Terminator
Calculon
Tin Man
Grounder from Sonic the Hedgehog
Atlas from Portal 2
C3PO
The main robot from Robots
Obviously there are hundreds. Who else do you see?