I'd definitely prefer the Blackbeard pirates last....I'm not sure that's going to happen, but I'd definitely prefer it.
They're the anti-strawhat pirates named after the most famous pirate ever, two devil fruits guy with his crazy wild wacky crew...who wants to be pirate king, who's ridiculous and silly, who planned for years as a unknown guy without a bounty, philosophically similar to the main character, with TWO devil fruits, declaring war against everyone at Marineford, who has honestly done more to move the story and his plans forward than most any villain in this series. How awesome were all his scenes at Jaya. And they're pirates!
Akainu, on the other hand to me, is a bit, boring stoic cookie cutter fascist character in the series. Reminds me of the one-dimensional racist Hody, who is basically a worse more boring version of Arlong. I understand that's The Point, but what I'm trying to say is that the most realistic villains are sometimes too boring and the weird dumb assholes are just...more fun. And I hope Oda doesn't make the final boss like...Imu. Akainu at least has the Ace thing, Imu wasn't introduced until like the last four years.