Have you ever tried to watch a movie and just couldn't get into it because you found the casting so ridiculous? Pam Anderson playing the president of the U.S., for instance, or Denise Richards playing a nuclear physicist (the latter actually happened)? The Fug Girls have documented 16 of those examples - I think my favorite is Freddie Prinze, Jr., playing Fred in Scooby Doo. One that I found really distracting that wasn't on the list (probably because it wasn't a huge part) was Mike Myers playing a British general in Inglourious Basterds.
Link via Go Fug Yourself