I find it dubious that anyone here will get better at choosing titles for their papers by reading these examples.
Nevertheless, I like the title "The homotopy category is a homotopy category" by Arne Strøm. I also like the very apt title "$\overline{\mathcal{M}}_{22}$ is of general type" by Gavril Farkas. The paper starts like this:
The aim of this paper is to prove the following result:
Theorem: The moduli space of curves of genus 22 is of general type.
