I can see you have a bit of an eye for composition, but I have some suggestions. First suggestion is your watermark is really obtrusive. I know you're probably trying to prevent someone from stealing your images, but my eye is instantly going to your watermark instead of the images.
1. The tops of the buildings are cut off. If you're going to do a city skyline, you really need to see all the buildings. In addition, I think there's too much water. Maybe try and recompose with less water and more buildings.
2. This is my favorite of the group. Interesting composition, and I find it pleasing to look at. I might have tried to get more of the building in frame, but that's just me and it's my preference.
3. This is a much better skyline than the first. You can see all the buildings. Unfortunately, I can see some darker areas of the photo, where I'm guessing the stitching was done. I've not done too many panos so I'm not sure how to fix this, or why it happened. Someone can probably give a better opinion on this.
4. Not bad, but this would have been a much better composition if it were centered. This is one of those times it would have been ok to break the rule of thirds. Remember, the rules of composition are more of guidelines. They aren't hard and fast rules that need to be applied to each and every shot.
5. My pet peeve is in this shot...the dreaded tilted horizon. It was the first thing I noticed. If the horizon had been level, and the subject tilted, I think it would look a lot better. Also, I'm not sure the shallow DoF really works here. It's difficult to make out what I'm looking at and there's nothing really interesting. It might have been better to stop down a bit to get more of that 'hardware' in focus. Also, I would recompose with the horizon and subject not centered.
