Most popular professions for the fictional treatment?

Yes, he was. Also, although the series wasn’t centered around him, a bicycle-delivery courier was a major character on the TV series Civil Wars.

Also, in the movie Quicksilver, Kevin Bacon played a bike messenger.

And another profession that you wouldn’t expect to see in the movies is beekeeper. But there were at least two movies featuring them; Ulee’s Gold and The Secret Life of Bees.

There’s probably at least one movie showing every single profession in the world. Even port-a-potty workers have the Australian movie Kenny.