I know this will vary with everyone's opinion but here's my line up:

-F1 BAR Honda

-360 Modena
-G35/350z/FX35
-Porsche 911 SC/Carrera MY1978-1989
-Honda S2k with SS Mugen exhaust

This is a selection from what I can remember at this point.

 

Ferrari F50 with MS Racing exhaust.
Ferrari F355 with Tubi exhaust.
Lamborghini Diablo
Porsche Carrera GT
Turbo Supra with straight-pipe and external wastegate.

 

Aston Martin Vanquish

 

MY03 Honda S2000 with stock pipes sound pretty good to me

 

Ford V8 - 5.0/351 or 4.6 SOHC/DOHC - both are superior to pretty much anyone's V8 sound these days.

 

I love the S2000's exhaust note but I heard a black 350z just fly through a parking garage last week and that sounded awesome. (not sure if he had stock exhaust though)

Here's my top 3 from the list.

1) S2000
2) 360 Modena
3) 350z

 

I was shocked as to just how good this lumbering(all relative, my friends) car sounds. I still opt for any heavily loping, big-a$$ cammed, true dual exhauust muscle car.

I also like the sound of the Dodge trucks with Flowmasters. Beefy.

 

I agree, especially with a Borla and X pipe.

 

g35 and fx's.

 

While I agree that American V8's can sound wonderful with an exhaust there is no sound like a 360 Modena with a Tubi exhaust.