I have (in the past) been disappointed with cars that I expected better or more from. For example; my friend took me out in his (ahem, borrowed) Ferrari 360 Spider. I expected to be blown away but it did nothing for me. Although it was not a 'hero' car of mine. Same happened in a friends Caterham, the grip was amazing but performance wa, wa waaaaa.....Maybe together we weighed a bit too much for it (had a 1000cc Honda Fireblade engine in it), not sure but.....
Back to the original question.......I have to say my hero was always the E30 M3 from when I was a teenager watching them at Donnington, Silverstone, Brands etc. All my favourite drivers drove them (Hoy, Minshaw, Sytner) and nothing looked like them or sounded like them.
I finally got one and fell in love all over again. Absolutely loved it every bit as much as I thought I would. (Not that mine is anything like those track monsters but the DNA is there certainly).That was nearly eight years ago (April) and I can't ever envisage a situation that would warrant me parting with it.
I have a similar crush on the Quattro Sport but never been in one.
However, one car I was expecting fireworks from and wasn't disappointed was my friends Supercharged Atom.....OMGoodness!!!!!! Most bonkers thing I have ever been in.