7. Neil Patrick Harris ("Harold and Kumar Go to White Castle")
He may have overplayed his hand by the third installment, but NPH's original cameo in "White Castle," playing a women-chasing, drug addicted, sex-crazed hitchhiker version of himself was hilarious. The role was only enhanced when he came out of the closet two years later, making the version he plays of himself that much more far-fetched and comically inaccurate.
6. Tom Cruise ("Tropic Thunder")
You know it's a good cameo when the random guy sitting next to you in the movie theater doesn't say a word to you until Tom Cruise's big dance number at the end of the film, when he turns to you and says "Holy shit! Is that Tom Cruise?" Where were you for the last hour and a half?
5. John Hurt ("Spaceballs")
It's always a treat when actors reprise their roles in films. But when they do it in a completely unrelated film, especially of a different genre, it really ups the comedy value. That's what we get here when John Hurt again plays his character from the movie "Alien," to a similar end. Well, except for the Vaudeville number, of course.
4. Martin Sheen ('Hot Shots! Part Deux")
Remember the whole John Hurt cameo? Yep, this one's kind of like that. Except now it's an actor reprising a dramatic role in a comedy film, while commenting on another dramatic role he played in another film to his real-life son about a movie they both starred in togeth-- Ow. Our brains hurt. (Martin Sheen's cameo comes at the 1:01 mark)
3. Kate Upton ("The Three Stooges")
Look, not all cameos climb to the top of the ranks because they are clever or funny. Let's just enjoy this one for what it is, shall we? Over and over and over again.
2. Alec Baldwin ("Glengarry Glen Ross")
Baldwin's speech in this iconic scene may very well be his finest work, and it's also been ripped off by so many pretentious sales managers worldwide who missed the point of the movie (or don't even know it is from a movie) that is deserves a high rank on our list for being truly unique.
1. Bill Murray ("Zombieland")
Bill Murray is the man. Everyone knows that. So it's obvious that if he plays himself in a cameo role dressed as a zombie, reenacting "Ghostbusters" scenes with his "Kingpin" co-star Woody Harrelson, and gets killed in a most comical fashion, nothing is going to top it.