Infernus was my favourite supercar/sportscar in IV and I still like it. I also really liked the San Andreas Infernus, dat engine sound!
Zentorno, statistically best supercar in all respects, but I'm not a massive fan. I'll drive it in free roam but on the track it can be a bitch to handle and I prefer the Entity XF.
Vacca is alright; really nice to drive as i found out on a track that was locked to them but other than that pretty much useless
Bati 801 is my favourite bike for cruising and it's brilliant at stunts.
Turismo was a nice car in IV, but the Turismo R is ugly and it can't compete in the super class
Cheetah is really nice to drive but i'm not a fan of the looks and it's not competetive
Carbonizzare isn't a very good car IMO, not only is it sort of ugly, but not very good handling and I've never seen anyone win a race in it.
I have no opinion on the Monroe or the Stinger because when it comes to sports classics, the Pigalle is my favourite.
Have to disagree about the Carbonizzare being ugly, it's a superb looking car. But then you like the Pigalle over the Stinger so we clearly have very different taste.
Since the Massacro came out the Carbo has been usurped but before that I used to win races all the time with it.
The Infernus used to be the stand out car in GTA but now it understeers, can't compete in races and simply isn't that much fun to drive compared to the other supers.