Driving Enthusiast 
2010 BMW M3 Convertible 2dr Convertible (4.0L 8cyl 6M)
Better than 911 or Benz AMG
 Hardtop convertible is best of both worlds.  Was also considering C63 AMG and 911 SCab.  The M3 performs better than 911 for $30k less, and out laughably out handles the AMG -- I also owned a C55 AMG previously and a Z06 Vette.  M3 has the best balance of comfort, power, and handling of any car I've owned.  I highly recommend the Tech Package for now other reason the the M-mode -- this allows you to change suspension, throttle response, and steering response with push of a button and transforms the car instantaneously (almost like a different car).  The V8 sounds incredible and can't wait til spring so I can hear it with hardtop down.  Must haves are Tech pkg, and upgrade wheels.  