For our first artist spotlight, I can think of none better than Gordon Lightfoot. He has long been a favorite of mine, and his core style is singer-songwriter with acoustic guitar, so his catalog lends itself well to the ukulele.
He may also be the most well represented artist in my song collection, although I haven't compared him to Irving Berlin or the Beatles, the two most likely contenders. A quick search for "Lightfoot" on the song page will bring up thirteen entries!
If you're not familiar with his work, I strongly recommend you get yourself a copy of "Gord's Gold," which I find a bit better than his "Greatest Hits."
What's your favorite Lightfoot tune? Don't have one? Well, there are links to Youtube for all thirteen songs. It will be an hour well spent!