Welcome to BYC! Throughout my childhood and lifetime I am going to say the RIR. The roosters can be very very aggressive indeed. I have two RIR hens now that are little snots. I have a mixed flock of Australorps, Cochins, Wyandottes, EE, Faverolles, BO, Dominique, NHR and hybrids. (I also hgave some young Delaware). The two RIRs are the meanest I have.
In the event you do not know what they are....
RIR Rhode Island Red
BO Buff Orpington
NHR New Hampshire Red
In the event you do not know what they are....
RIR Rhode Island Red
BO Buff Orpington
NHR New Hampshire Red