It depends on what you are looking for.  Economy then definately go diesel.
They get excellent fuel mileage (around 50 mpg is the norm) and usually
require very little maintenance (this has alot to do with how well it has been
cared for in the past).  Some people are offended by the diesel rattle, the
small black puffs of smoke that they emit, and the fact that they take off a
little slower from a stop.
If you are looking for something with zip and personality then maybe the
Cabriolet is the way to go.  I would probably have a garage to put it in
though to keep the top in good shape and just remember that if you are not in
Florida then you will be keeping the top up most of the time anyway so if you
are in a cooler clime you might go with a Jetta or Golf with a sunroof and be
better off (less road noise and warmer in the winter).  GLI, GTI, and the
normal Jettas and Golfs are all the same as far as reliability goes (which is
high).  I don't know much about the 16v GTIs or GLIs though.
Have fun and if you are close by I can sell you my '85 Jetta diesel that gets
56 mpg for $1500.
Ken Wilford
John 3:16
(609)-327-0027