I generally don't go to chain restaurants when traveling that are available where I live--with few exceptions. (For example, the Olive Garden in Times Square would be off limits when visiting NYC, but Waffle House is acceptable since there are none in California.) As for exceptions, going to somewhere like McDonald's in another country can be acceptable if the purpose is to try a menu item that isn't available in the US.

As for food in general, I'm not too big of a fan of mushrooms but I'll eat them if provided.