Notes:

Role call:

Sym-Bionic Titan from Sym-Bionic Titan
One of the robots from Sky Captain and the World of Tomorrow
Dendoh 9 from Gear Fighter Dendoh
Jaeger Gipsy Danger from Pacific Rim
MEGAS from Megas XLR
Super Robot Chogokin Dai Guard from Dai Guard

The Iron Giant is the 'I'.

Sauce
http://danielmead.deviantart.com/art/Giants-8-358464225