I'm all for rivalries in fiction, as they are often great vehicles for some nice character development. Oddly, in spite of having so many different iterations, there are lots of potential character rivalries that were never tapped into, even though some of them seem pretty obvious to me. Like, wouldn't it be awesome for a more G1 oriented Prowl and Shockwave to develop a kind of respectful rivalry, with them being kindred spirits as 'bots of logic? Or how about a G1esque Ratchet and a Prime oriented Kockout? With both of them having somewhat hedonictic traits, I could totally see them being the two big party animals back in their pre-war years at the medical academy, currently being torn between fond memories and ideological\moral differences? How about you guys? Are there any characters you think were meant to have such a relationship? Would their rivalry be comradely or more antagonistic? You can choose anyone from any faction, continuity or media, it's all up to you. Have fun!