Since around two years I'm a user of Cinematica, a payed Software. This application can help you, to simply managing your movie stuff in some simple ways.
Features who I like:
• You can create different Librarys in different folders
• All your stuff can be stayed at it's place. So in Cinematica you simply have a link to the file and yep, it's no problem to move the file in another Subfolder... Cinematica will still have it under controll
• After dragging a Movie in the list, it will generate Thumbnails (as you prefered in the settings) from the complete movie just in seconds
• You can create folders / intelligent folders as "Collections"
• Create keywords
• Insert a Poster
• Insert a Description
• Create own Tabs
• You have the choice to watch the movie in the app or in a external Player
• and some more
And this is how it can look: You can get your copy here: http://www.xericdesign.com/cinematica.php
For the full version you need to pay 39,99 Dollar. It's not a really low price, I know, but it is worth. With a bit of Luck you can catch it with a bundle, so I got my copy on bundlehunt.com. I'm sure that they will make an offer again in the future, so let your Mail adress on that page and keep an eye on it or you know other ways to get it :-X