SS100
Daimler Double-Six
4 1/2 litre Low Chassis Invicta
Any of the big vintage Bentleys (pre Rolls-Royce)
Hispano Suiza
Bugatti Royal

But the music of the 100/4 Healey was sweeter than the 100/6, and the Healey Alvis and the Healey Riley were lovely too.

I also love the sound of the TR2 to 4 series, and the Morgans using the same engine.

The MGB sounds great, but the MGA Twin Cam was really a nicer car (if a bit fragile)

For the 6-sylinder freaks, how about the MG Magna variations, and the XK series Jags?