Ive seen 3 rumbles, all from Season 1.0

Lightweight
I cant remember them all, but Backlash, Das Bot and Tentamushi were in there

Middleweight
Virtually all the Middleweight robots

Heavyweight
This had 18 robots (NS = Not Sure)

Vlad the Impaler
Tazbot
Frenzy
Overkill
Punjar
Kill-O-Amp (NS)
Suicidal Tendencies
Gammatron
Mjollnir
Biohazard
Blendo
Voltarc
Bender
Killerhurtz
Knome 2
Monster
Nightmare
Mauler


By the End, only Biohazard, Voltarc, Tazbot and Vlad the Impaler were still moving.