Anyone know what breed this is?

I've never had Americana's before but they look like the photos I've seen of them. It's probably to early to tell for sure.

 

Going to have to wait a while I'm afraid. Several breeds start out like this because this pattern/color is common in several breeds.

 

There are a couple of reasons for that. First, the one of the right is younger and has no wing feathers so that would make it look fluffier. Second, none of them would be Ameraucana; they might be Easter Eggers. EEs are a bit of a mixed bag in that they don't have to look the same (since they aren't an actual breed). Some have muffs and beards (the fuzzy faces) and some are clean faced. As chicks those with muffs will have fuzzy cheeks which makes them look fluffier then those who don't. But as Grey Farms stated, there are many different breeds that have the chipmunk pattern as chicks.

 

Ameraucanas have blue/gray legs and feet..Check that out.

 

I don't think they are Ameraucanas or Easter Eggers myself. I think they are more likely Leghorns, with their pattern, yellow legs, and single combs.

 

Ameraucanas are pea combed, only. Easter Eggers can have any comb type. But as you stated they usually are pea combed due to pea comb is dominate trait passed on from the Ameraucana parent.

 

I have the same ones. Like posted by previous posters; there are different breeds that look the same.
These look a like a lot like my little Brassy Back Old English Game Bantams, that might be what they are...
Where'd you get them? A Farm and Home store? If so, when you bought them, were they marked as Bantams?