One word of caution: this thread may not contain the worst font in the world - there are hundreds of thousands and the answer is somewhat subjective. These are just six of the very worst.
1. Times New Roman
Designer Devi Prasad gives his verdict: "Yes it is one of the most used font in computer history. You should not use it because of the same reason."
2. Brush Script
Prasad again: "Script font, seriously?"
3. Bleeding Cowboys
Case closed, no further questions.
"It's virtually unreadable and I can't think of a single use it might have," graphic designer Rikard-Rodin says.
Notably, when Avatar used it for Na'vi subtitles.
6. Comic Sans.