We usually do a seafood fondue - prawns, firm white fish, ocean trout, bug tails, crayfish and sometimes scallops but they tend to spit. We also have a bowl of tempura batter by the side which tastes divine because it is so fresh. Also have a bowl of par cooked sweet potato, brocolli, cauliflower, snow peas, baby eggplant (if it looks any good) and sometimes potato. We use the metal fondue with oil and normally have store bought sauces or Asian sauces from the local Chinese restaurant. As a side line, also grab a packet of uncooked prawn crackers to throw in to the pot. Also have a bowl of steamed rice on hand. Have also done with beef and lamb in the past with obviously different condiments and no tempura.
For dessert fondues, the most popular ones I ever hosted were the Toblerone or Mars bars ones. We had lots of fresh fruit, marshmallows and slightly stale cake.
As to pastry in a fondue, I have put dumplings in made with wanton wrappers. They were fine. Don't know about any thicker pastry though.