I love the gulf coast area. Most beautiful beaches in the country, imo. The Emerald Coast is a wonderful vacation spot.
As to the best area, it depends on your budget and your vacation style. Do you like quieter beaches with upscale restaurants? Do you prefer a spring-break feel, with mini-golf, bars, and amusement parks? Or do you like beach cottages and farmers' markets? Do you want to stay in a condo or a cottage?
My favorite area is the Seaside/Rosemary Beach area. It is upscale, with quaint shops- and it is very bicycle friendly. It is quite expensive, and many of the rentals are not directly beachside. Many people rent small cottages and bike to the beach. There are farmers' markets and food trucks. It has more of a neighborhood feel. My 13 year old loves Seaside. She prefers it to PCB, but again, it much more expensive than PCB, and it is harder to find a place directly on the beach.
If you like a more inexpensive place where you can find reasonably priced condos on the beach and lots of hustle and bustle, you might try Panama City Beach. It is one of the cheapest places in the area. It can feel a little dirty, though, and it is not good for bike riding. It has mini-golf, water parks, amusement parks, go-carts, shopping, and restaurants. There is a more expensive side and a cheaper side. We have a friend who lives in an oceanfront condo on PCB. She loves living there. She likes the hustle and bustle, but when she wants a quiet place, there is a beautiful beach state park and wildlife sanctuary just down the road from her.
If you are looking for something in between the two, then you could go with Miramar Beach or Okaloosa Island (close to Destin). Still plenty to do, still reasonably priced, but not as much action as PCB. A little quieter. Still not great bike riding areas because of all the traffic, but there are some great resorts on Okaloosa with water parks and tennis, and Miramar has a lot of small neighborhoods with rental houses where the neighborhoods might have tennis and pool.
Destin is great, too. More like PCB, but a little more upscale. Some beautiful resorts in Destin with pools and tennis.