I can’t really take a lot of credit for this one. Alfred forum user Efty Edge was working on something similar to this. He ran into a few issues with it so I stepped in to help him out and put something together that was a little simpler and seems to work great. Simply use the dl keyword and pass a Youtube URL as an argument to the workflow. This workflow makes use of youtube-dl to download the Youtube video. Videos are downloaded, named the title of the Youtube video and saved to your Desktop.
Original forum topic found here for reference.Download