Speaking of euphemisms....
One night when I was a student at Rutgers U., my friend Emily and I were hanging out in her dorm room with the door open when two girls walked by carrying on a loud discussion about a guy they both knew.
"He's just not the hottest crayon in the box" one said with authority.
"You mean the brightest crayon in the box?" asked her friend.
"No" she snorted in reply, "I mean he's not hot."