I grabbed the Fight Club 10th anniversary version. If you really care about the diff between picture quality then you might want to get it, but if you already have the special edition dvd and don't give a fuck about blu-ray so much you really don't need to get the blu-ray at all. There's one extra feature where you can mix your own audio for a basement fight scene, but that's about it for anything new.
Word up on Monster Squad though. I grabbed that on dvd a few years back. Lots of good features on that dvd.