Worst that come into my mind are ESFx-INTP, ESFJ-ENTJ and ISXJ-ENTP, and I've thought about those kinds of dynamics the most.
Best? Huh, how much I embrace the negative thought. I'm not that sure about the positives. ENFP-ESFP, ENTJ-INTJ, ENTP-INFP.
Just my first thoughts, even though I've thought about all those dynamics previously, too.