+1 for AA Flagship lounge.

Not just the lounge, but also the staff. We were booked on the second last MIA-MSY flight of the night which broke after we boarded. The flight was cancelled and the rebooking line was hundreds deep. I went straight back to the flagship lounge and she had us booked on the final flight of the night. Our bags even made the connection!

I was the only person rebooking at the flagship lounge. She was confused why nobody else was there (she actually didn't believe me that the flight was cancelled initially, as nobody told her and the system wasn't updated for almost an hour after we deplaned). We actually had seats on both flights until the cancellation came through.

Sorry - going OT - point is, the lounge especially the staff is the best you'll find in MIA.