You may get a Thundercats/Machine Robo Crossover, but you won't get Gobots crossover cos good ol' Hasbro owns the rights for Go-Bots. They would've acquired the rights when they took over Tonka in 1991, hence why Transformers has been using Gobot names/characters/likenesses since 1993.
G2 Gobots
G2 Go-Bots (subline) -- later repainted as Spychangers in RiD
Transformers Go-Bots (aka Transformers Big Adventures. They had their own cartoon!)
G1 Gobots (eHobby)
Armada Leader-1
BotCon Bug Bite
Megatron kills Cy-Kill
MovieVerse Crasher (called Fracture for legal reasons)