Criterion is a company that creates special editions of DVDs. Usually have special features like anamorphic transfer (for the earlier movies anyways) and documentaries. Like with Armageddon, you got anamorphic transfer and outtakes. Most of the time Criterion versions are worth the money but sometimes they just is suck, compare the features and ask yourself if it's really worth the extra $15 to $20 to hear the director talk about the movie. Sometimes the improved video transfer alone is worth it though, almost like watching a totally different movie.