My best buff on buff encounter was my JU-88's encountering a flight of Ki-67's, each of us RTB from runs.
Finally tally was me losing 1 JU-88 and 2 others shot up bad, and him DT out of there with 1 lone surviving Ki-67. It was a fun fight though. He fighting with those Ki-67's lousy turns and poor formation ability, me trying to stay OUT of his 20mm firing arc. Wish I'd have recorded that one.
Back when I ran high B-17's, I dove down on an enemy flight with a good 10K alt advantage. Wing struts were protesting something fierce, but a passed down through the enemy formation guns blazing. Sort of a hit and run thing, but also fun. Did some damage. Parts carved off. Some smoke and vapor trails and probably some ded gunners.