The only ones that aren't completely full of shit are Ron Paul or Kucinich, but both are quite eccentric and have no chance in hell in winning.
The most dangerous candidates for us would be either Rudy or Hillary just because they are so connected with the current political machine.
Obama is done for, maybe Edwards has a chance by virtue of his good polling in some of the early primary states.
Unless something dramatic happens, I think Rudy will be up against Hillary in the GE, and some sordid affair of Bill will be trotted out tainting her run somehow, and Rudy is going to dress in drag again, etc, etc, etc I'd rather kill myself then see either of those assholes win.