Ferrari 360 challenge. Almost crapped my pants.
The ezno was cool too,

.
SRT-10 viper is next in line...
Followed by a modded VR6. They truly do sound incredible when you push them. Very distinct roar. Part of the reason why i bought one.
SO hey, i'm byast..
here's a sound clip of what i'm talking about... yeah, the quality sucks, but.. you get the idea...
http://members.aol.com/iamthegtiguy/VLgtivr6.wav