Metroplex.
Trypticon. (LOLLLLLLLLL)
Fortress Maximus.
Scorponok (G1).
Size can be inconsistent, but these four were pretty much autobot/decepticon bases.
To my knowledge only Metro, Trypt and Omega Supreme have been featured in Transformers games, none of them playable and all of them appropriately massive (compared to
your characters, also Transformers) and lumbering. So it still lines up with what I was saying.
edit: speaking of size inconsistency, Sky Lynx and Astrotrain should have been massive, but were always portrayed as the same size as everyone else in robot mode.
Eh, I doubt any of the toys creator realized or gave a shit about what size a space shuttle is, let alone kids (and that includes me). "It looks like a plane, it must be about as big as a plane... which itself can't be much bigger than a truck".
I have no idea how big omega supreme is. no one does.
Or how powerful. Remember how he single-handledly crushed the entire Decepticon army in his comic debut, including megatron? Remember how he is later one shotted by Laserbeak? Good times...
triple edit: anyone who can figure out this guy wins the thread
That's Broadside; a couple friends of mine included it in their podcast (like a decade ago) about the worst 10 Transformers of all time; to this date we don't know if it's supposed to be able to land on itself or what. I've also always loved this: