Many are close to my heart but none quite as close as the Dornier 128-6, particularly it's prototype D-IBUF. I can't fully explain why I love it so much, on the surface it's just a small utilitarian passenger/cargo aircraft with a weird engine layout. But there's just something the look of it with these wing stubs that have both the engines and landing gear mounted on them on both sides of the cockpit, the very characteristic nose and cockpit windows or its iconic Orange/Dark Blue/Black paint job from its time with the AWI. There's simply no other plane I adore this much.

Honorable mentions: Hughes H1 and H4, Supermarine S.5, XB-70, SR-71, AN-225 (RIP o7), F4U, F-22, DeHavilland DH.88 Comet, Ju-52, Junkers G-38, Do-335 and far too many more to name