EVERY tropical place I've ever been to is my favorite! :lmao:
How tropical are we talking here? Because even Charleston, SC probably seems "tropical" when you're in Illinois.

I love Charleston, it's one of my favorite places in general; Savannah, too.
I've been to beaches all over Florida--absolute favorite there is probably St. George Island because it's beautiful and a little remote, therefore less crowded than the Daytonas of the world.
The only TRUE tropics I've been to was a trip to Grand Cayman, Half Moon Cay and Bahamas/Nassau. Half Moon Cay--OoooLALA!! Awesome, awesome place! Again, part of the attraction to me was that it wasn't quite as touristy and populated as Nassau. Drop-dead gorgeous, though, and the weather--well, when I was there it was probably 110 in the shade (not that there WAS any shade, lol), and BRIGHT; honestly, that's what I really remember, how bright it was. Even with sunglasses on, I found myself squinting sometimes.
My dream tropical destination is Belize, and maybe Costa Rica.
I'd also love to go to the Galapagos Islands, but I think that's not truly tropical either. But it's hot, and it's beautiful--good enough for me.