Luffy's crew vs. Blackbeard's crew. I believe they will have a 1v1 for each member of the same role/rank. Although I originally thought Burgess was gonna go vs. Zoro, because they are both the 1st mates I believe, Burgess is not a swordsman.
Anyways, my order of most wanted fights is
Luffy vs. Blackbeard
Zoro vs. Mihawk
Roger vs. Garp
Franky vs. Vegapunk (not Kuma, though that would be interesting as well)
Ace vs. Kuzan/Aokiji