I think my favorite so far was when one of my high school teachers said he expected to see me in the news someday for doing something great. I still don't believe him, but for someone to think I would actually change the world felt like a big deal to me.

but that question is in the present tense, so I think the only way you could truly impress me with a compliment is to come up with something that is (a) new and (b) just on the edge of believability