Do not miss the Sanibel Lighthouse is you're a fan.
J.N. "Ding" Darling National Wildlife Refuge is a really cool place to visit.
Bowman's Beach is a pretty popular area on the island to hang out.
Attached to Sanibel by a small bridge. An equally beautiful destination. there are a lot of beach houses for rent here. Be aware of the crowds as we have had shoes stolen in the past (of all things, right?)
The best beach island, in my humble opinion. Get there early for parking and a good spot on the beach, especially during tourist season. If you are going to stay in a hotel, make sure to book early and be aware that hotels in the area are pricey.