9. Metal Sonic/Metallix/Mecha Sonic - Sonic The Hedgehog Series
Though I’m including these as a single entry, Sonic fanboys would end me if I referred to Sonic the Hedgehog 2’s Mecha Sonic as “Metal Sonic”, so I’m obligated to say... I know, guys. I know they’re not the same robot, you nerds.
But, each of the robotic versions of the blue blur deserve their place in this list. Mecha Sonic, for example, shows up as the mini-boss prelude to Doctor Robotnik’s Egg Gundam Thing in Sonic 2, and truly terrified me as a bairn.
Though it’s arguable that Robotnik himself was tricky, Mecha Sonic was no pushover - with no rings to use as a comfort blanket, a single hit from the buzz saw-scraping menace was enough to end Sonic (and with as many fakeouts and feints as he used, end you, he would).
Robotnik would update the design and create Metal Sonic, an equally-tricky foe who showed up in Sonic CD for a death race in Stardust Speedway Zone - an endeavour made slightly less enraging by the super-catchy 90s dance music, something that eased the pain of being crushed again and again by reminding you that you haven’t listened to Rhythm Is A Dancer in ages.