It's almost a cliche now to talk about the impressive calibre of actors who appear in comic book movies these days. We should probably all just accept that the huge mainstream successes of the major franchises now mean that seeing Oscar winners and hot rising stars are naturally going to be attracted to the genre. To a certain extent, the surprise does a disservice to the medium.
But it still remains genuinely surprising when really top drawer A-Listers appear unannounced in Marvel movies and it seems to happen increasingly, as if it's becoming a trope of its own to go alongside the Easter Egg fetish. Whatever the cause for it, it's led to some seriously jaw-dropping cameos - mostly from actors - that mstly managed to fly under the radar until fans saw them on release.
And when those actors could have been legitimate draws, had they been announced as part of the cast, seeing them held back for secret roles is all the more impressive. But which were Marvel's finest...?
13. David Hasselhoff - Guardians Of The Galaxy Vol 2
Given James Gunn's obvious love affair with the music and culture of the 1970s and 80s that expresses itself so obviously in the Guardians Of The Galaxy movies, it shouldn't have been a surprise that we'd get a great cameo in there somewhere. What was surprising was that it was David Hasselhoff that was chosen.
Peter Quill wears his heroic inspiration points on his sleeve and the sight of him being met with one of them - the Hoff specifically in Knight Rider - was one of the best moments of the entire series (it also inspired the brilliant Xardu Hasselfrau gag). And fair play to him for being so game.