Buff Orpingtons are the friendliest...heck I would say that most any of the Orpingtons are friendly....they are the Golden Retrievers of the poultry world. My Buffs layed large to extra large eggs.
Barred Rocks have become a favorite of mine...there is no doubt. They are a strong well built bird, I enjoy their historical status as a Heritage breed. They lay large to what I would call a jumbo egg. Some can barely fit into an egg carton.
Ameraucanas are a very aggressive breed. They are talkative and can be noisy at times. I would definately try them again, but as a monoculture, not in a mixed flock. They are however very prolific layers, winter weather does seem to get them to slow down more as compared to other breeds. Most of the eggs are a nice medium size, with short runs of larges thrown in occasionally.
The Black Sexlinks are good layers...not a lot of personality though. I do have one girl that is a jealous bird, she goes after any bird that gets to close to me. She is the flock boss and really defends that position in the flock. Prolific layers of large to extra large eggs.
The Welsummer has always been a breed that I want to try. I've had false starts, but they just have an appeal to me. The replacement flock that I'm working on now are all Welsummers. Not laying yet, so I have no opinion as to rate of lay.
The Australorp has been a breed that always comes to the forefront when I'm considering my next replacement flock. I always hear good things about that breed.