As someone already posted, first choice by far, the SR-71.
If you would classify the Space Shuttle an aircraft, the Space Shuttle.
And lastly, as far as modern aircraft, the F-4.
Older aircraft, the B-17 because my father flew them in WWII.
I've flown the DC-3, I have about 200 hours in them, DC-6, the Stearman, T-6 Texan
So, that leaves the Ford Tri-Motor, Mosquito, Spitfire and the Boeing 314 Clipper.
Oh, and of course the P-51 and the P-38.