For your creative pleasure, we created a wiki tagline for every city on our website. Anyone can login (with a user account or anonymously) and edit the tagline to see the "official" tagline for the city change instantly. The taglines are limited to 140 characters. Let's face it: the wittiest taglines are often quite brief.
Here are a few examples from the many dictionaries on the website:
Some of my personal favorites are ones that are adapted from famous movie taglines, such as the following:
Detroit, MI: "In Detroit no one can hear you scream" (adapted from Alien's, "In space no one can hear you scream")
What's neat is that you can click on "history" to see the entire history of the wiki tagline. For example, here is the tagline history for Madison, Wisconsin. Once you create a tagline, it becomes immortalized. If yours is good enough, it might just stick around on the front page for a while.
So, go to City Dictionary, find your city, and share with us your best tagline. They don't have to be official-sounding, or even entirely based on reality. Taglines, just like resumes, should be aspirational (wink).