Love the Harrier - way ahead of it's time. But...
Civil - Lockheed L10-11 Tri-Star, especially in TWA colours.
Military - has to be the SR71A - no contest. The fastest, most
wicked looking plane ever conceived i my opinion, even shading the
F117. I had the privilege of seeing two flying (on seperate
occasions) at RAF Mildenhall. First was one taking off very early
one morning, however by the time I'd stopped the car t'was merely
an ascending black arrow against the grey sky. The second was much
better - during an open day in, I think, 1984. It came in halfway
through the afternoon and did a fly-past before landing. Absolutely
stunning. Afterburners on, and beautiful bright shock bands clearly
visible in the flame.