If you're unhappy with most of the "frontrunners", you can make your voice heard on Americans Elect.
Current front runners on Americans Elect include Buddy Roemer, Dennis Ross, Trey Gowdy, Allen West, Ron Paul, Steve Stivers, Garry Johnson, Mike Pompeo, and Ann Buerkle. All of these are tagged as Republicans. This might signify that many who consider themselves Republicans may be very dissatisfied with the current version of the Republican Party.
I didn't go past the first nine listed alphabetically (all starting with A), but there are probably a hundred or more people nominated so far. The top five tracked are Ron Paul, Barack Obama, Jon Huntsman, Buddy Roemer, and Gary Johnson.