Dunno about discontinued stuff, not something that is gonna pop into my head right now... I am really partial for a KFC Zinger Tower meal though, best one I ever had was at this restaurant that didn't have teenagers or immigrants working in it, but rather it was in a small town near the sea with some middle aged and older women working there.... Man you can tell those women knew how to cook and cared about their customers because every aspect of it was better in terms of preparation/cooking/presentation, not like you usually get in most KFC stores.
Otherwise I really really love Greggs spicy pepperoni Pasties, more of a specifically british thing though.