You can't go passed any year M5. They were the best saloon cars in the world for each era.
On the 50/50 weight bias, my car is 51/49. So BMW do a great job also on turning out cars. The Porsche 951 is a great car too. Easily chipped to have over 225kW.
Oh, the Lotus Exige and TVR Sagaris for pure madness