7. Mercedes 6.2-liter M156/159 V8
They discontinued this glorious V8 and replaced it with the fantastic M178 already featured on this list. But, this naturally aspirated unit is so good and since they installed it in so many models up to 2014, this makes it modern and available on the used car market.
The secret of the M156/159 is its great construction. This is a classic, sporty V8 engine with 6.2-liters, perfect block and head construction, high revving capacity and 571 to 631 HP on tap. This was the first engine AMG designed on its own. Besides the guaranteed performance and speed, this engine had one of the best soundtracks of all time, achieving it without any sound enhancers.
Basically, the M156/159 was the last great classic V8. The engines that succeeded it had either smaller displacement or forced induction to achieve the same power level. They produced this engine in large numbers since they installed in 10 Mercedes models, including the mighty compact C63 AMG sedan and the SLS AMG sports car.