17: E28 M5
The BMW M5 has been around since 1984 and the car is still a massive success. The combination of a larger body and more power made the M5 a smashing success. Compared to the M3, the M5 models have their own unique personalities. There is nothing cookie-cutter about this car, and the E28 is one of the best (via Classic Trader).

The unique thing about the E28 M5 is that there’s a massive enthusiast network behind it. This means finding parts and repairs is never more than a click away. On top of that, the E28 itself is a notoriously reliable platform. This low-level maintenance is the key to the beauty and engineering of the E28 M5.