yFlicks is a movie player and organizer that not only lets you view and arrange movies in static groups — its versatile tags feature lets you categorize your movies any way you want. You can even tag your movie automatically by querying Amazon's online movie database, which gives you the additional benefit of having the corresponding DVD cover art downloaded automatically. And once you've done so, creating smart groups based on your tags and subdividing those smart groups by tag values will let you browse your movie library by Genre, Actor, Director, MPAA Rating, or Year, for instance.

And if you're a Front Row fan, you'll love the fact that usher mode lets you access the full complexity of your yFlicks library via Front Row.