Robert Downey Jr. is hilarious in it, and Jack Black has his moments, but the actor who steals Tropic Thunder outright doesn't even appear on the poster. Tom Cruise, who has an extended cameo in the movie as a belligerent studio executive, is so over-the-top funny he makes you forget all about that appearance on Oprah and the other freaky stuff.
Because it's a cameo, there aren't any photos of Cruise in the film's presskit. There's only this widely circulated image of him between scenes on the set. But trust me when I say you walk out of Tropic Thunder thinking Tom Cruise is cool again. Like Top Gun-era cool.