I have as much fun with the videos as I do with the mixes and I try not to go the obvious route with the footage I use. Like the "Ride The Wild Wind" video, I thought "Okay, cars and whatnot...," then got thinking "No, that's too easy and it's what people will expect!" So I spend a while thinking about what to use. Sometimes ideas come easier, like I'll think of an old movie and will be like, "Yeah, I'll try that." "Mr. Bad Guy" was a mix I did a while ago, but couldn't think of what to use. I felt that since it was a character singing about himself and how great and "bad" he is, anything I use starring people will sound like I'm doing a tribute video to a movie villain (like Darth Vader or the Sheriff of Nottingham). I was flipping through YouTube movies and someone linked the "Let's Face It!" atomic bomb short film, so as I was watching it I saw the arrows flying over the US and thought "Let's go chasing rainbows in the sky!" and it all clicked. Turns out it was hilariously perfect, I think.
I also like sometimes going way off-center with the video, like "Tonight" (a love song) with "Night Of The Living Dead" (the classic zombie movie), because romantic movie footage is hard to use, since it's not very exciting. The closest I've done is "Love Me Like There's No Tomorrow" and the "She Makes Me" cover in the Sheer Heart Attack Covers Experience compilation video.
Sorry to ramble, but I've been eager to know if people even cared about the footage or were only interested in the remixes.