*sigh* It appears I am the only person in the world, but my sweetest little chicken is a White Leghorn. Next is my Barred Rock (actually they are tied I suppose). 100% sugary sweet on both of those girls.
The sweetest, friendliest, chickens I ever had were Polish Cresteds. White Crested Black Polish.
Of course, I kept them under my shirt when they were chicks, and I gave them tons of attention. They liked to perch on my shoulder as chicks. Four of them looked alike and were un-named, but one I named Lorraine because she was really friendly and I could tell her apart from the others. I said her name a lot, and I actually think she learned her own name, because she would jump on my shoulder when I crouched down and said "Lorraine", even when she was a grown hen! One of them grew up to be a rooster, and he liked to hop on my shoulder, too. The other 3 hens were more like typical chickens, sort of shy.
Sadly, they were all killed by predators. They were free-range, which is not safe for Polish Cresteds, because Polish Cresteds have poor vision, and they can be ambushed easily. Their head plumage blocks their vision.
My Barred Rocks are bold and smart, and they are survivors in their free-range lifestyle. I had a pampered Barred Rock chick named Screebert, who was extremely friendly as a chick, and still eats from my hand, now that he is a grown rooster.