This is tough, because I think most of us would simply settle for "All of them!" Until then, my list:
P-39
Mossie (Come on, Dave, what's taking so long? Oh right, the other plane you're working on.
)
Privateer (-2 single tail with dual .50 blisters)
V-22
V-280
T-7A (On Dino's to do list, but it will be awhile)
Cessna Crusader
Rutan Catbird (Long shot, but why not)
Glasair III RG
Velocity V-Twin
Convair 990
Gripen JAS-39
Rockwell Jet Commander
Rockwell Sabreliner (Isn't one of these being worked on? Or was that P3D?)
Lockheed Jetstar II
F-86H
That should cover it for now. It's difficult to minimize the list. I should note that I didn't add anything that was made in the past by Carenado, such as the Aero-Commanders, as I figure they will eventually convert those to MSFS.