User blog comment:BrolyFan76/Blackbeard vs Strawhats/@comment-3425840-20120517083737

From present situations:

Luffy vs Teach (even Captain Obvious knows it).

Zoro vs Shiliew: Sword with swords.

Usopp vs Auger: They are both shooters.

Brook vs Lafitte: The creepy duo!

Franky vs Pizarro: Confirmed cyborg vs predicted cyborg.

As for the rest, no fucking clue (I am pretty certain about the first four though).