In my past experience with chickens, the Plymouth Rock breed was a pretty well mannered chicken, as much as any of them are. I think my worst experience with chickens was with Rhode Island Reds, they were just plain mean.
I really like the Buff Orpington also, I had a hen of that breed that would hatch eggs.
I miss having chickens, it's been about 20 years since I had them. I used to live in the country and moved into town, and the town doesn't allow people to keep chickens.