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?
Ford 351 Cleveland or Windsor. Other than that the Ford Kent engine
Ever heard of a Clevor? It’s a Windsor block with Cleveland heads. Kind of an old race engine trick to get the lighter weight and small bellhousing pattern of the Windsor, but flow of the Cleveland.