I've had over 13 different breeds, most of them at the same time, and I find it a triple tie with Shamos, Araucanas (
real ones, not EE's) and Polish.
But I might choose Polish over the rest.
Shamos and Polish are both equally very friendly, non-skittish, intelligent, reliable layers, have more meat on their bones than people think (
although not hatchery Polish, half of those are pretty skinny) they're very eye-catching, very hardy, but my Polish I can trust more than my Shamos when it comes to fighting other chickens, and my Polish I can trust to be strong and healthy in our climate, especially as a chick.
Also Polish come in some amazing colors. Shamos come in neat colors too but most of their neat colors don't fit to the body as well.
Another thing is, Polish lay white eggs. When you've been around chickens and chicken owners long enough you get really tired of brown eggs, and find if someone has something other than brown it is blue, green, or dark brown - But a good rainbow basket is seriously lacking without a good contrasting WHITE.
Also, my Polish go out there and explore the pasture/wilderness more than my other two favorite breeds. And believe it or not, they make some very fast growing hybrids.