A couple of issues...what's reputedly the best, and what's the best that's open right now? Over the years, the destination I've seen most often touted as 'best in the Caribbean' is Little Cayman, along Bloody Bay Wall and Jackson's Bight, with Cayman Brac a close second (reputedly dives average a little deeper, IIRC from someone's trip report). On a
Cayman Aggressor IV trip, out of 25 dives, 18 were at Little Cayman, and yeah, I can't say I've seen better. But the Caymans aren't open right now.
But for reef, I was about equally impressed with the outer atolls via the
Sun Dancer II (since renamed the
Belize Aggressor IV). A live-aboard isn't the only way to get out there, but for some of us, perhaps the best. Belize is open.
I heard Turks & Caicos claimed as such a destination, so
I tried them via live-aboard. I enjoyed the trip and was happy with the boat and crew...but for coral reef diving, sorry, I rate the Caymans and Belize's outer atolls higher. I hear T&C is open.
Bonaire is nice reef, particularly to the far south (e.g.: a site called Sweet Dreams). I've only had one trip to Curacao, diving the eastern region near Willemstad (not Westpunt where I'm told the best diving is), but I liked it fine. You've been to those, and Roatan. I've not yet been to Roatan; it's open! We see reports from Curacao, and some people made it to Bonaire.
If you haven't been to Cozumel, you owe it to yourself to go. I'm not claiming it's the best...but it is good, the topside fun and has good, affordable food, and overall trip costs from the U.S. tend to be good (I don't know about from Panama).
Tres Pelicanos & Casa Mexicana, Cozumel Sept. 2018 Report -
Tres Pelicanos/Casa Mexican Trip Report Sept. 2018
My Research Notes from Planning Cozumel Trip -
My Research Notes from Planning Cozumel Trip
Richard.