My #1 choice for domestic would be Amarillo, however because of our great hop shortage *gasp* I was forced to look for alternatives.
My LHBS literally just received a new group of hops from New Zealand two days ago, and yesterday I was lucky enough to grab big bags of Riwaka and Pacific Hallertau.
Riwaka has to be the most citrusy, tropical, bright, and fruity hop I have ever seen/smelled. It's definitely an aroma hop at 4.5% AAU however when I rubbed the leaves it had an amazingly slick texture (high prevelance of oils).
Last night I brewed up a batch of Amber with 4 separate additions of Riwaka and Pacific Hallertau....so far I can smell it coming out of my airlock!
grab some if you can find it.