Hmmm...I really don't have a favorite quote. There are several that I like, such as:
"Wagner's music is better than it sounds." Samuel Clemens
"I don't know the key to success, but the key to failure is trying to please everybody." Bill Cosby
I was reading "A Little Princess" last year and this passage jumped right out at me:
"Never did she find anything so difficult as to keep herself from losing her temperwhen she was suddenly disturbed while absorbed in a book. People who are fond of books know the feeling of irritation which sweeps over them at such a moment. The temptation to be unreasonable and snappish is one not easy to manage. 'It makes me feel as if someone had hit me.'"