Here's a guide if you didn't recognize everything (you're extremely good if you did!):
Chupperson Weird and his best friend R.O.B.
Sapphira and her dog (Amber?)
Kojinka, her papier-mâché Yoshi, and her cat
bobman37 and
BenA long time ago some n00b made all these awesome pictures with the Deezer caricature and I saved them
Boo_penguin offers you a tasty beverage
Insane Steve, right, gets his DDR on (the only known picture of IS?)
Luigison, comatose, hallucinating vividly
People from some Halloween ad
EclipsedMoon loves catgirls and Hooters girls (EM found mysteriously murdered shortly after pic was taken)
Deezer gets a visit from schnorks
I think those are Bird Person's legs
Lizard Dude, TEM, and TEM2 a.k.a. RipTard camping somewhere along the Missouri River
Suffix and Watoad are a little shy
If only PictoChat used WFC, MEGAߥTE and Watoad wouldn't have had to travel so far to talk
The incredibly rare act of eating during E3
Mr. Melee and his BFF Chupperson Weird