Having a favorite hand wont help your game, but it does make it more fun. If you have one specific favorite hand (suited and everything), then when you catch it, its more fun to play than the rest. Even Brunson loves showing off his 2 10 to the crowd when he wins with it (He has stated that he always plays that hand at least once in each tournament just for fun). It just adds fun to the game, and will only hurt you if you let it.