The ratio that is suitable for your object. We don't know what you want to emphasize on. Try for yourself a bit (16:9 could be an idea) and see how it comes out. Main question: what do you want to show? Where is your main object? But first, straighten up to remove the tilt.
Read up more about composition.
The picture is much better than before. There's still some slight tilt though. You may wanna try to align the edge of the image to one of those skyscrapers.
Regarding ratio. Like what Octarine has mentioned, what do you want to show us? I believe as per your title you want to bring our attention to the Esplanade. But isn't it weird that the Esplanade being your main focus, merely occupies less than 1/8 of the photo and we can only see the roof?:think: :dunno:
Ok, so I presumed that you took the photo and walked away?
Have you thought of walking around the building to explore it further? How do you turn a view which was "kinda" nice into something fantastic? Have you considered that if the Esplanade was your focus, was there a need to include so many other distractions? How do you avoid these distractions? Or were you really interested in the whole scene?
Good photography isn't just about photographing something nice but more of how do you photograph them. You'd find that you have to go beyond simply clicking the button and formulate a train of thought when being presented with a scene. Resist the temptation to take the photo without having a design intent. It will not turn out well most of the time.
Please post a new version of the picture and keep the former one. Otherwise other people cannot see what was changed and how it improved.
If the outline structure caught your eye then why do you include these concrete plant pots in the picture? You could step on them to get a better angle. Also, the sky looks promising for using a CPL.
good effort in correcting the photos after shooting. 16:9 crop looks good as well.
still... it can be improved. get distractions out of view.
for example, there're leaves on the left side of the first photo. those could be cropped away or move more to the right to avoid capturing these with the subject.