I practically grew up in Fernandina Beach (before it was the much tonier "Amelia Island") and have played literally hundreds, maybe thousands, of rounds at the muni. Most recently played it in July of this year. The West and North sides are just fun, fun golf. They've got a nice, natural feel, interesting movement and turns. The West is long, the North short and South tight (very, very tight). It's a great bargain and great fun.
The other courses on the island don't do a whole lot for me, particularly at the prices they charge. Jump in the car and head to 1-95 and north an exit or two, though, and you can play Osprey Cove, a very nice Mark McCumber design in St. Mary's.
And no one has taken me up on it yet, but I'm telling ya - if you're willing to drive one hour inland, to Waycross, Georgia, arrange a round at the wonderful Joe Lee hidden gem, Okefenokee GC. You'll be glad you did.