I'm more interested to see your research. I believe you, of course, being a frequenter of /ck/, /v/ and /pol/ and thus having what I feel is a good test spread, but in order to make the claim as fact rather than opinion... Indeed, it must be an extensive set of observations.
Of course you're also talking about establishing objective criterion for 'best board,' which is something that one cannot exactly do from an enjoyment stance.
Perhaps I really like getting into arguments with liberals, /pol/ is certainly the best board for that.
Perhaps I like yelling at atheists, well, then I should probably be on Reddit. Is Reddit the best place on the internet? Jesus Christ no.
Maybe I like futa. Welcome to /d/!
Perhaps I like Traditional Games and... Historical stuff. Then I'd probably say /tg/.