Alan Ducasse & Guy Savoy
Lucky you. Two of my favorite restaurants in Paris. ADPA is superb and more formal than Guy Savoy. Are they worth the price? To me, yes they are the epitome of what three star dining in France is all about. They are both extremely expensive: the tasting menus can run over 300 Euros each. GUy Savoy is more "americanized" in terms of Service. M. Savoy's signature dish, the artichoke soup is superb, and a must have. At ADPA I recommend the langousines with cavier as well as the famous Baba, a must have at any Ducasse restaurant. Bon Apetit. You will have a wonderful time at both restaurants.
I personally never understood what's so great about Ducasse -- except the high luxury, the menu holders and the like. Savoy is a wonderful human experience, of generosity, show and civilisation. I also disagree that the artichoke soup is so great -- Savoy did not serve me a good one in a long time. Just listed some specialties, but really, let the captain guide you. Then the question is also about what you expect from the restaurant, how experienced you are with fine dining, what kind of food you like, etc.