Hard to decide because none did really something special. I think I have to go with Chisora and Ruiz jr (love that guy!) in 2nd place. Wlad (on significance) 3rd.
I think you have to go with Chisora Resurrected his career and beat a dangerous unbeaten contender in Malik Scott plus beat two decent Euro Heavies as well as capturing the Heavyweight title. On top of that he also came into fights in the best shape of his life which has meant improved speed and punching power. Also people have to remember Chisora didn't take up boxing till his 20's and is only really now coming into his peak. He is the ONLY heavyweight to have faced the Number 1(Vitali Klitschko), Number 3(David Haye) and Number 4(Robert Helenius) Heavyweights at the time he fought them. All this within 19 fights. [YT]?v=Vr9R_OLpzoE[/YT]
Vitali for wanting to run for president atleast he will be challenged at that .other than that a heavyweight has not really done anything of note
Wlad fought his sparring partner and then disgraced himself and the sport against Povetkin. Chisora got my vote.
Chisora's wins are a disgrace to this sport. Brits accept robberies when there boys are on the good end of them.
Stiverne started the year off well beating Arreola but has been frozen out since due to Vitali holding up the title. Wlad is an obvious choice, won all his fights, still champion and with Vitali relinquishing the belt is the clear champion now. But the Povetkin fight did more damage than good. Chisora is on a nice winning streak but against lower level opposition so isn't in contention. Leapai had a great year basically won the lottery by beating Boystov and earning a title shot. Personally I don't think anyone deserves the distinction of being the heavyweight of 2013, nobody really stood out.