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?
Honda F20C, B18C, and the Totoya 1LR-GUE. All of them are extremely reliable, high revving formula 1 inspired peak examples of Japan engineering at its finest.