I've liked most of John's various haircuts over the years, with the exception of his Future State look, which I thought looked a little dumb. But I also loved the JLU's idea of John going bald as he got older (remember, he was meant to be in the 40s) and finally shaving his head, so future John having this full head of luxurious hair decades from now felt wrong.
My favorite John look, however, is his original 70s afro with neckerchief. That has not and cannot be topped for sheer style.