I don’t know a ton about foreign motors other than surface level stuff like the 2JZ, Wankel, etc. so please forgive my ignorance outside of US motors.
However, in my eyes, it doesn’t get better than the simplicity and easily available power of the SBC, BBC, and 6BT. What are your all time favorites and why?
Young me; Chrysler 318 and Chevrolet 283.
Middle age me; any mercedes in-line gas or diesel.
Old me; an electric motor.