Do I have to go with 4 wheels?
If so, Aston Martin would be right up there. Any of the DB9 generation as performance isn't really a major problem with the baby version.
I used to love the AC Cobra but I'm not sure about a convertible anymore.
If I can get away with 2 wheels, I really like the look of the Benelli Tornado:
I very nearly bought one 3 years ago, but the reliability record was dire. So I bought my Triumph: