Chicken Marsala is my all time favorite meal.
Believe it or not, Olive Garden is one of the best at making it.
I prefer Veal Marsala, but I too was enlightened to this wonderful dish about 5 years ago. I'm quite sure as a child I would have found Marsala repulsive, but as an adult I adore the wine sauce. Combined with some mushrooms and good breadsticks and pasta it's devine, chicken or veal.
I prefer the Marsala at Carrabbas, but Olive Garden is good as well.
It's easy to make yourself actually, too. Just don't go too strong on the wine, it's very potent in taste.