What am I doing wrong here

I like the way this photo came out but to me it kinda looks fake or cartoonish in a way. Does it look right to you? If not, what am I doing wrong?

Not sure exactly what you were trying to accomplish, but here are my thoughts.

1) The wall in the lower right is somewhat distracting.
2) The clouds are blown out.
3) The little blue box on top of the sign looks weird.
4) The sign itself is very vibrant, it really pops.

Perhaps try reworking the image keeping the rule of thirds in mind.

I think that what worries you is that it's a cliche'.
OK, so maybe it is. If you like it, defend it, and let the Devil take the hindmost!

I am in full agreement with what Robert Lay said. So it isn't technically perfect -- so what -- it is what you wanted and I think that it looks fine.