I've played with pretty much every character, and no one feels as badass as Captain Falcon. He's a superhero speed demon (kind of contradictory, eh?). I cannot seem to feel as strongly for much of the other characters as I do with the ol' cap'n, but maybe that's because half of them are aliens. Goroh and Octoman have always been a good second place.
Mr. EAD was based off of Mario wasn't he? Firstly, he sports the "roundness" and the 'stache. Secondly, he has a power star for a belt buckle. Thirdly, EAD is the largest section of the Nintendo game development studios and is an acronym for "Nintendo Entertainment Analysis and Development". They've developed most of Nintendo's 1st-party titles.