I've been re-watching some of the original cartoon and thinking about the specific rivalries explored. One thing I notice is that, in Transformers, there is a lack of one-to-one correspondence between personal rivals, as was common in other 80s toy lines.

Of course, there's Optimus Prime versus Megatron, but later on things get more complicated, with Rodimus Prime versus Galvatron, Ultra Magnus versus Galvatron, and Ultra Magnus versus Cyclonus.

The same is true of sub-groups and gestalts. Yes we have Dinobots versus Constructicons, but we also have Devastator versus Omega Supreme.

Within G1 but beyond the cartoon, there's other patterns too. The box art always suggested to me Dinobots versus Insecticons, which I think would have been interesting to see in-story.

So, my questions then are, what are your favourite rivalries, and what neglected rivalries would you have liked to see, in G1 or other continuities?