It's the Dolphins for me. If you look at the teams and how they performed this season then you can realistically think the Dolphins can improve just by getting healthier.
The Eagles have the best OL in the game, one of the best DL, 2 brilliant WR's, a great TE and they still came up short.
Same with Dallas. Great OL, 3 All-Pro's on it, might be right behind the Eagles. They have a great WR, good TE, great pass rushers and a good secondary. They also came up short.
How do those 2 team improve as much as Miami will when Miami inevitably upgrades the interior OL, gets a TE that can create separation and gets it's best pass rushers back?
Miami made the playoffs while missing 9 starters for much of the season, their 3 best OL played less than 50% of the snaps this season. The team will improve dramatically just by getting healthy.