"best" in what sense? Most power? Cheapest? Most economical? (if such a word can be applied to any engine from the later Skylines
) most driveable?
Most potential power would lead you to the RB26DETT, no doubt. But for everyday driving I personally don't like them as much as an RB25DET. You need more revs to get them really going than you do with an RB25DET. Of course, go they definitely do, and I'm guessing that's probably what's going to influence your decision
You could go with a CA18i from an R32 GXi - probably your most economical option
But you might as well push the thing and run behind it. :hehe: