We like to do one special event a month. Sometimes they're big, sometimes they're small. This is a small one. We buy a PG-13 movie that's recently been released (like say, World War Z) and then we have our youth group come over our house, eat popcorn, drink soda, and watch a movie. It gives them an extra option on a Friday Night, let's them share in our lives a little bit, and gives them something light and easy to invite an unchurched friend to.
If you have students with strict parents in your youth group, either pick a PG rated flick, or let all the students/parents know ahead of time what movie is being shown so they can decide whether or not their student can attend.