In the Transformers franchise, many characters have, over the years, taken on the same names. Megatron, for one, ranged from raspy and idiotic (here is proof he's a dummy-it's in the last minute of the video) to raspy and insane (yes, I consider that Galvatron to be Megatron) to smooth and brilliant to just mind-numbingly stupid to, well...
Megatrons are usually depicted as a threat, but only in one case (Beast Wars/Beast Machines) was the threat an intellectual one. The rest of the time, it was a nearly purely physical threat (with occasional doses of supernatural mind control etc.) that often even in that respect wasn't that intimidating. Once Optimus shows up to kick him around, Megatron usually folds. (There were exceptions to this-in his more powerful forms in the Unicron Trilogy, particularly the Cybertron series, Megatron in upgraded form was terrifyingly strong, and not that weak beforehand.)
It's kind of funny that many Megatrons, most particularly the raspy G1 version, have this incredible mystique around themselves, when in general they're these really pathetic, even whiny guys. Only Beast Wars Megatron was consistently depicted as a truly threatening force, and that wasn't even reliant on his physical power. (Ironically, he was the one most often referred to as a fool; more ironically and also sadly, one of the biggest Megatron fans of all time [I'm not naming names, mostly because any long-term Transformers fan will know exactly who I'm talking about] HATES HIS GUTS. I have a pet theory that this is the fault of the Japanese dub of Beast Wars, but it's a dubious assumption.)