I think you're approaching things from the wrong perspective. You need to first determine which beach you want to visit. Florida has more than 1,000 miles of coastline -- second only to Alaska, which is beautiful...but not really the beach scene many picture

.
Once you decide
which beach, there will be numerous good options. Beachside hotels are not hard to find in Florida!
With older kids and adults, I would ask them
where they want to go and
what they want to do.
Do they want to gather seashells...or do they want to party until dawn?
Do they want to walk along tranquil beaches with the water lapping at their toes, or do they want to surf?
Generally, the Gulf Coast -- from Marco Island all the way to the Alabama border -- is the tranquil area. NE Florida, north of Daytona, is also more laid back, but on the Atlantic with real waves.
From Daytona south to Miami, you have sun and surf. From Ft. Lauderdale to Miami Beach, you have nightlife -- with the serious nightlife folks focusing on South Beach with occasional forays to
Liquid at the Fontainbleau (which is well north of SoBe). (Understand that "partying" SoBe style is WAY more than you might do at home...or in college...or on spring break...or other amateur venues.)
The Keys are the Keys -- featuring fishing, diving, and drinking. A Keys vacation is a Keys vacation, and should not be confused with a beach vacation. There aren't many "beaches" where we could say the word with a straight face, but it's a great place with a style of its own.