As a former ramp rat, I’m biased toward aircraft you could identify before seen. Based on that criteria, I have to nominate the TPE331. “Don’t let that MU-2 sneak up on you” said no one ever.
Regarding the RR Dart, I did have the misfortune to connect/disconnect the start cart for the start-up of a chartered Viscount. Truly the British answer to Phil Spector’s “Wall of Sound.”