I've had my share of 'em too but the best story I ever heard was third-hand (both parties are now deceased). In the early eighties I worked for an accountant who had once worked under a CPA in a nearby large town. My boss (an honest and truthful man) told me he was an actual witness to this scene:
A regular customer, grouchy and notorious for his chronic complaining, came in to pick up his return. The CPA quoted a reasonable fee. The patron promptly threw a fit, let out a string of curses, and roundly chewed them out for all manner of excessive charges, slipshod work, along with many outrageous slurs. My boss said the CPA simply sat there through the diatribe; then calmly stood up, picked up the return, tore it in half, then quarters, threw it down on the desk, and said: "Now, get your a$$ out of my office!"
I've always wanted to do that.