Like everybody else I can't list a single choice.
Jet: Hawk T1a, best little flying sports car ever built.
Higher performance piston: Bulldog: good enough in every respect, leaving an overall combination that is a huge amount of fun.
Lower performance piston: Grumman AA5 (just a great little tourer, nothing faintly glamorous about it)
Microlight: Medway Raven; handling that is as near perfect as I've ever seen.
G