They're all pretty nice.
#1 - As someone else said, my eye is immediately drawn to the light in the corner. I didn't even notice the sunset until I was about ready to move on to the next picture. It seems the interesting part of that shot is the scene in the courtyard of the hotel.
#2 - Looks nice. I like the composition, how it is, but it seems there's too much negative space in the photo in general. It just looke like there's too much water. This could be an opinion, however.
#3 - This is probably my favorite. I love the composition, with the moon kinda in the leaves of the last tree. Looks like you used a tripod and a slow shutter speed, which would account for the tips of the leaves having some motion blur. Must have had a bit of wind. Some people might have a problem with that, I think it looks fine for this shot.
#4 - I think I would have liked this one better without the fill flash. A silhouette of the palm tree would have been more effective I think than having it brightened by flash. I might have had a different opinion if the light hadn't dropped off the tree and bush at the edges and they were evenly lit. Fill flash isn't always needed, and in sunset shots, silhouette's will help set the mood a bit. Other than that, this is an excellent composition. It's just the kind of shot you'd expect to get from Hawaii, or another tropical beach.