I tried the Mushroom & Swiss burger recently and let me tell you it's amazing. I haven't tried the other two but I bet there even better.
When I ordered my burger it seemed much wider than a normal size big mac burger and inside it had some kind of sauce and mushrooms. So if you don't like mushrooms I don't recommend it. The other two if your interested are called the Deluxe, Bacon & Cheese. It's so cheat. One day when you have nothing to do and your close to McDonald's and order yourself one. (:
I tried the Mushroom & Swiss burger recently and let me tell you it's amazing. I haven't tried the other two but I bet there even better. 
