I really don't know. I brought up the Rubly thingy in the other thread because I recalled reading about his screw-up in 1995.
In reality, I've been watching football for just one year and been a fan for not much more. A thing that I would've hated to see is Hornung being shipped off to the Saints in an expansion draft. Also seeing Jim Taylor being traded to the Saints a short while after that.
Maybe Foster-Dave, Cheesey or our viking friend Vikesrule remembers this?
EDIT: On the field. I should really read before I post.
I think a worst moment on the field is nearly always tied to injury's. Like you guys said, Sharpe certainly comes to mind.
I still don't like Sapp's hit on Clifton either, though.