"Pretty" is in the eye of the beholder. Lots of people find australorps to be pretty, but I personally don't find them very interesting to look at (although I guess it could be argued that their sheen is a subtle kind of pretty). For flashy, most birds with white markings (speckled, mottled, spangled) are generally pretty flashy. Laced birds tend to be pretty flashy too, even the hens. And birds with Columbian markings (colombian wyandottes, light/buff sussex or brahma, etc) I think are quite pretty. They aren't quite as flashy as laced or mottled birds, but the contrast is nice anyway. I can't tell you from experience, as we are still waiting on our first chicks to come in about a week and a half, but I can tell you that I was looking for some eye candy hens for my small flock and we went with speckled sussex, exchequer leghorn, and silver laced wyandotte (although we really wanted blue laced red). We also got some EE for the colored eggs, and because I think puffy cheeks will be cute, but not necessarily so much because they are "pretty" compared to the other breeds.