I don't know of this counts but Settlers 2, the original one. You go through hell, some of those missions can take 10 to 15 hours, you slay all the bad guys, you win it all, and what do you get?
A BAD DRAWING OF A FUCKING BOAT!!!!!!!
C'MON MAN! After all that would some dancing girls kill you? A song, I mean a different song? Maybe a picture of your populace erecting a statue in your honor? How about a simple "You rock!" or "You are a God!" I'd take that. That would work! :D
I'm guessing the developers expected no one to actually finish those missions and took an "oh, fuck it" policy at the end.