I'm a HUGE car guy...and the ones that make my head turn that meet most of your criteria ...
more than 2 seats...fast...fun...reliable...umodifed...
2008 BMW m3, 4door/2door...any BMW M car some available w/ a drop top.
2008 Lexus ISF 4door
Older Subaru Impreza WRX STI/ Mitsubishi Lancer Evolution IV MR
Audi S4/RS4/S5 coupe/sedan/convertible
Mercedes CL63 AMG...any mercedes AMG
Cadillac CTS V
Infinity G37 coupe
Maserati Quatraporte/Gran Turismo
Aston Martin DB9
Alfa Romeo 8c (2 seater)
Ariel Atom (2 seater)
...Keep in mind that the higher end mercedes amg's, and the Italian and British cars will cost more than 100 grand US.
These are just to name a few off the top of my head...don't know what other criteria you like...I have driven most of those cars and am very familiar w/ them