I think Nintendo chose Wii over Revolution because Iwata kept saying "Revorushun." :P
When I first heard that they were going to change the name to Wii, I was like OMG, Nintendo is doomed! But the name has grown on me and Wii is definetely the better name. Sure Revolution sounded cooler, but Wii is a better name for their strategy in getting everybody to play games. They kept it simple and it worked.
The worst console name award has to be given to either Xbox or Gamecube. Actually, now that I think about it, alot of console names are pretty dull, except for some of Sega's consoles like Dreamcast or Genesis.
edit: Nintendo Entertainment System was a good name too. But then Nintendo just got lazy and started adding prefixes and suffixes to Nintendo, just like what is happening to xbox and playstaion. But to create a brand name, I guess it's not such a bad idea. Just start off with a good brand name :)