Spencer Fisher should be the next in line.
Im surprised no one has mentioned him yet.
The man is well rounded and can really finish a fight brutally through submission or (T)KO.
Got to give him credit for taking the Stout fight in a few days notice and cut weight. Spencer fought a good fight against Stout and BARELY lost. If he hadn't gassed from cutting weight so fast, im sure he would have finished Stout.
The man loves to fight and he seems to have a champion spirit to back up his skills.
They should do a Spencer vs Guillard before Spencer goes for the title.
Just because I want to see what happens when you put two fireballs like them in a cage.