ferrari enzo v12- god like
viper srt10 v10- B-E-A-Utiful
427 zl1 v8 - heaven on earth
350z/g35 v6- nicest sounding v6 ever
mazdaspeed3/wrx/evo i4- turns peoples heads like u wouldnt belive.
edit: than their is 2 cyl bike motors like harleys and ducati's.
and rotary which the rx8 is sweet music to my ears.
listen to the sound of mazda's furai. 1 of a kind if u ask me
thats my though on each motor i think sound asom.