I don't have many doubles. Siloam Double Classic for me (typically, apparently) throws a single or two at the beginning of its bloom season and then doubles from that point on. Condilla is always double.
I have Peggy Jeffcoat, Prester John, and Royal Eventide but am still waiting for the first blooms on those. I also have Nell Dean coming this spring, so I will be able to report back on that one as well.