To me, 8 is clearly the best, composition wise.
IMHO you should learn to watch the lines. With ultrawide lenses you easily get converging lines when you tilt the camera only slightly downwards or upwards. With buildings or anything rectangular in the image, this can be very disturbing, or a great effect, it really depends. So if you get converging lines, do not get them by accident, but get them the way you want them to converge.
1, 3 and 5 suffer the most from this problem.
Image 2 has potential, and so has 6. However, they do not seem composed carefully.
For 2 my tactics would be to either get some lines parallel to the frame, or at some very pronounced angle.
Number 6 is tilted clockwise and slightly off centre. In wide angle photography, slightly off something often has a very strong effect. so you have to be very precise when composing.
Also, one can see the limitations of the lens in number 6 (distortion/ bent lines). Not your fault, but you could correct this to some extent by software.