The good old BAe 146-100 - in the early days there were some legendary demo flights. Stripped out, minimum fuel and just a couple of guys up front, the British Aerospace demo pilots used to do amazing things at Hatfield, showing off no doubt, but mind-blowing for a commercial jet airliner. Around the world they've landed on grass strips (just let some gas out of the tyres) and all types of rough unpaved strips. Could drift in to the Hatfield runway almost silently and stop as if a carrier landing - absalutely incedible - no thrust reverser noise. All those RJs and Avros out there today can still play those tricks - converted as a business jet, its just about the largest thing you could possibly get in (and out), legally and sensibly into your local golf club! Definately best aircraft for drug running and importation of illegal immigrants......nobody can hear you land on your privately prepared airstrip. Rather large radar signature though.
However, the De Havilland Dash-7 is also pretty incredible when it needs to be - aircraft carrier compatible!
Falcon 50 though best of all business jets, by a mile.