IMHO, are all crap. The best and nicest engine I have seen from Nissan is the KA. And that is because it is simple. There are 14 components in the engine. (not counting individual springs etc.)
Nissan has time and time again proven to me to fail. I am not impressed with anything they have designed ever.
The only thing I will tip my cap to is the skyline r32, r33 and 34. I have experienced these and they do impress me. Everything else however is the definition of crap.
Nissan FTL