My girlfriend almost got in a fight in Boots, apparently:
gf: (to shopper rudely taking up all the aisle space) "excuse me, can I just squeeze past"
evil lady: let's gf past and then gives loud humpfy sigh and gave big big evil eye to gf
gf: "well, i did say excuse me"
evil lady: "well you should have gone another way" (more evil evil eye)
gf: "well how about trying to be a nice person"
...then she ran away in case evil lady decided to punch her the face.
That's a cutting final remark, I'm sure you'll agree. It would have put Hitler in his place.