I just realized I hadn't offered MY 2 cents! I love Daytona. I've been going there since I was little, and before I visited, there were always stories of my mom's family vacations there as a child, so there's a lot of sentimentality wrapped up in it. Still, I like it on its own merits, too. We normally stay at the south end (just north of the Dunlawton Bridge.) There is driving on the beach, which is unique, but there are also areas where driving isn't permitted.
I think what I'm realizing is the same exact beach can be so different, depending on water conditions. Last August, we spent a week at South Daytona. The water was pristine and clear. The beaches are nice and wide, and the sand is powdery. There aren't a lot of shells, so tender feet aren't bothered. I've seen it look cloudy and murky and rough, too. Rough days are super fun for surfing or boogie boarding, or just jumping the waves!
Sanibel has its charms, but honestly, I like our East Central beaches better for an overall "beach" experience. I will say that I thought Sanibel was MUCH prettier (and so were the shells) during our Labor Day visit, versus two July trips we've made.
St. Andrews State Park near Panama City had gorgeous beaches when we visited in May 2008! Really, it looked like something straight out of the Caribbean. However, we visited again in July 2009, and it was murky and ugly. It's so crazy how different things can be. I'm sure it was just the time of the year, or the crowds.
We love the beaches at Clearwater, but the paid parking and crowds were daunting. Daytona has spoiled us with all of the free parking available, in lots, at waterfront parks, and at some on ramps.
Finally, in Miami, the beaches made by the expressway built out to Key of Biscayne are surprisingly nice! We like the clear water and little waves - great for playing with the kids.
This in no way represents all Florida beaches! But give them a try if you're a beach fan. I for one love them.