We just got back from a Florida dive trip. We were there Feb 25 - March 6. We dove Key Largo, Key West, Looe Key, Crystal River and West Palm Beach. Heres my thoughts.
Key Largo - good wreck diving. We went with Blue Water Divers and would HIGHLY recommend them - they were the best dive op if the trip. Conditions were tough - very strong current and low vis (40 ft or so) - but a good time. The Spiegel Grove was very impressive.
Key West - very disappointed - poor vis and the reef was unimpresive - very damaged.
Looe Key -0 great for critter watching. Saw green and spotted morays, reef sharks, turtles, octopus, lobster -etc. Very shallow diving - only 30 or so max so your bottom times are long. We dove with Looe Key Dive Resort and would recommend them. They were a bit of a cattle boat operation but we did enjoy it.
Crystal River - waste of time - 10ft vis maybe.
WPB - most enjoyable diving of the trip. Decent reefs and TONS of stuff to watch. Definately the most fish to see of all the places we dived. Eagle Rays, Nurse Sharks, lots of turtles, green morays, spotted morays etc etc etc. If I had to recommend one place - I would pick WPB. We dove with Diving Solutions and I would recommend them.