Leaving them in the dust and enjoying your life.
Push them off a building. Nothing like the direct approach.
the best revenge is living a well lived life with no regard for getting back at others, but to holding yourself up to a higher standard.
Screw their best friend
Let them live with their ugly?
give them a mirror?
Happiness is the best revenge. But I do love a good revenge though.
Don't lower yourself to there level, just smile ,it hurts them worse. It's like a tick, if they know it bothers you they will dig in deeper
Smile and ignore them...you'll confuse and make them so mad!