Originally a popular British TV show starring semi-successful comedian Jimmy Carr. Now is used to describe any group of any foolish or comic people. Can be used to describe an activity.
"Aren't you a little concerned we look like 8 out of 10 cats?"
"Nah, everyone wears suspenders sometimes."
Used when you happen upon a particularly beautiful woman, and then skillfully using the 1-10 scale as a rating - you twist it into a different type of ending - with the meaning that you would like to fuck this woman.
Me - 'Oooh, u see that?'
U - 'Uh huh, thats real nice!'
Me - 'Rating?'
U - ' Out of 10? ... I'd give her ONE!!'