This is just a question that popped into my mind, and I was curious as to what you all think. Ultra Magnus and Rodimus Prime seem to be the two main contenders, but I think that I lean a bit more towards Rodimus Prime.

 

Himself!

 

In the cartoon it was definitely Rodimus as they were leaders of their respective factions. Ultra Magnus' rival was Cyclonus as the much more competent 2nd in commands though I think they'd get along if they didn't have to fight.

I believe the bios hinted Ultra Magnus and Galvatron were rivals to hide that Galvatron was literally Megatron reborn.

 

For me, that would be Rodimus. Both represent a new start for the Autobots and Decepticons and their showdown was one of the best scenes in TFTM. Beside, if Galvatron prefers fighting with Ultra Magnus, who is going to be poor Rodie's archenemy?

 

Himself.

 

I lean more towards Magnus. Again, I like the opposites dynamic. Magnus is order, Galvy is chaotic insanity.

In fact, if I were gonna give Roddy an enemy, it would be Shockwave. I mean, I don't mind Roddy tangling against Galvy, but I feel Shocky is a much more fitting rival for him. Roddy is pretty emotional, prone to outbursts of anger and has self-esteem issues, Shocky is extremely logical and very confident in his abilities.

 

I agree with this. I love Roddy, but Galvy isn't a fitting archnemesis for him.

 

The fanbase

Particularly @TheUltimateBum

 

Rodimus Prime.
Cartoon Roddy is the chosen one... A bitch slap and tossed him like trash. One on one Galvatron is no Match. Rodimus lacks experience to which Meg... Galvatron has Millions of years. It's brains vs brawn.
G1 Comics it's Magnus.
WFC everyone

 

I felt the Galvatrons rivalry started with Ultra Magnus but after he had the sweeps "kill" him he was no longer considered a threat until glavatron was bested by rodimus

 

Technically it should be Rodimus Prime since they are their respective faction leaders, but when I watched season 3 and The Headmasters I always felt Ultra Magnus was more Galvatron's nemesis.

 

Galvatron and Magnus lock up in Web world and maybe one other cartoon episode.
In the cartoon he punched his own troops more than anything else. Rebirth it's Magnus troops vs Galvatrons Magnus looses. Headmasters Magnus dies at the hands of Sixshoot.
The only time Galvatron and Magnus are Rivals is...
UK Marvel Comics. Unfinished between the 2
IDW/Marvel continuation Regeneration one and Magnus Kicks His But. Finished him by squashing his head in his hands Epic.
Galvatron is the embodiment of Chaos. A destructive force of nature. His Archenemy is anyone or anything that gets in his path.

 

Well with the toys Rodimus Prime never made sense standing next to Galvatron he was just too small. However Magnus and Galvy were about the same size. Plus in the G1 commercial it says Ultra Magnus is Galvatron's sworn enemy.

 

I've always gone with Ultra Magnus.

And hey, this also answers the question of Do you consider Ultra Magnus to be an official Autobot Leader?!

 

C. Unicron

 

Not easy to answer, because you could argue it should be one, it appears to be the other, but it makes more sense to be none.

In the sunbow cartoon Galvatron was the Decepticon leader while Rodimus Prime was the Autobot leader. But although technically true, the cartoon presents it more like Ultra Magnus was Galvatron's natural enemy. This makes sense from a toy perspective: they were the size and the same price class, thus Hasbro likely wanted the cartoon to promote Magnus more than Rodimus.

I've also come full circle on this since the 80's. Back then I wanted the leader of the good guys be able to fight the bad guy leader. But there's of course no need for this to be the case. There's more to being a good leader than being physically strong -- actually, that's not even needed as long as someone among the troops is strong enough to take on the bad guy leader.

But in the end, I don't think Galvatron works as a leader. I feel he was handled much better in Marvel where he's a rogue element, only out for himself and convinced he doesn't really need anyone else. As such, Rodimus Prime is not his natural enemy. With Ultra Magnus a soldier it makes more sense that he confronts the chaotic Galvatron.

Although I also agree with @TheUltimateBum that Rodimus vs Shockwave just works better, if I could travel back in time and influence Hasbro, I would have Cyclonus step up and become the Decepticon leader. Concluding at the end of FFoD that Galvatron was too much of a loose cannon and take command. And Rodimus Prime vs Cyclonus (with better toys that scale to each other) also works really well.

 

Probably Ultra Magnus. But Rodimus is definitely close.

 

I thought his arch enemy was everyone around him.