Whenever I'm having a bad day, I usually resort to watching this classic Friends clip - the infamous "PIVOT!!" episode...you may know the very one I'm thinking of. This clip never ceases to make me laugh...when this episode first aired, my friend Nayely and I were rolling on the floor dying of laughter. Still today, we continue to use the "PIVOT!!" in an aggravated Ross voice - if the mood needs lightening.
If you ever find yourself in a similar situation, I suggest you give it a try, it almost always brings a smile to my fave.