The sweetest rooster we have ever had is our Faverolles roo, Mr. Hen. Faverolles roosters are known for their sweet temperament. That said, I am sure there are others out there who have experienced a mean one... but overall they do have a great reputation as good boys and he is just awesome!
We also have a Mottled Java, a Cuckoo Marans and a Barred Black Olive Egger rooster... all are very respectful and we enjoy having them.
We have had mixed results on our Bantam Cochins... out of 3 roos of this breed... 2 of them are super sweet boys... but 1, Mango the Terrible, ended up in the pot.
The meanest roosters we have ever had were a pair of Light Brahma's... they were awful... they attacked and chased us and were terrors. Also we had some mean little Bantam Naked Necks roosters... they were fighting and trying to kill each other when they were just wee chicks... we had to put them in separate brooders - eek!