I think generically, the "worst" degree is one that is highly specialized, and overstaffed. People point at liberal arts, but the problem with it is there are a lot of people with those degrees and not enough jobs that use them effectively. You could get a hyper specific degree but if there are 10 people that work in the field and 10 jobs and isn't growing, or you could get a very broad degree that has 100,000 jobs but also has 100,000 people working in it and also isn't growing, you're just as out of luck.

You have to find a degree that matches what you're willing to do or learn with who is willing to pay you/grow. Even then, there's no done deals. 10 years ago Computer Science was one of the top degrees to get, now people are fleeing the programs.