In #1, though the flash fired, the Inverse Square Law of light prevented it from adding very much light to the fountain, and you had 2 light sources, each having a different color temperature, causing a mixed lighting white balance issue.
The composition lacks tension with the fountain and the implied horizon both being centered weak further weakens the photo.
#1 I like it, there does seem to be a lot of dead space at the top and the water gets a bit blown out towards the bottom. I would probably redo the cropping a bit.
#2 and #3 just don't do anything for me.
#4 you have some sort of strange thing going on with your crop/border there.