Six among threes 

A term used to describe a not entirely unattractive person (usually female) when they are surrounded by decidedly unappealing individuals, thus making them seem more aesthetically pleasing than they actually are.

John: "Hey, did you see that hot politician on TV last night?"

Jim: "Let's not get carried away, John. She was a six among threes."

Six among threes by Posty the poster June 21, 2011