It looks a lot like a dahlia to me....http://www.worldofstock.com/closeups/NPF6394.php What ever it is , it sure is pretty.
I'm with Gardenmama on this one. I also think it's a Dahlia. There's one called "Seattle Novelty" that looks very much like yours.
I think the yellow is like my Dahlias. My Dahlia this year mot as pretty as last years ( photo / image / picture from glendann's Garden )