I have the collectorz.com product, and have used it for several years. It's probably the best pure-cataloging software there is, but it's limited in that all you can do with it is catalog.
What I REALLY use is DVDLobby, which is part of the MainLobby suite (PC only, available here:
http://www.cinemaronline.com ). The beuaty of DVDLobby is that, like Movie Collector, it loads all the movie info via an internet search. The great thing about it is that it can be used to control a DVDChanger, ZoomPlayer, or TheaterTek. I personnally store most of my DVDs on a Sony DVP-CX777ES 400 disc changer, and store shorter ones (kids movies and such that are less than 1 hour in length) on a HDD for playback via ZoomPlayer. With this setup, I can browse my collection and select movies to play seemlessly. For HDD-based playback you can very easily add multiroom capability (can too with the changer, but you'l have to play the same movie in every room). Unforuneately, DVDLObby's cataloging capabilities are not as robust as Movie Collector, but it's still evolving.
If you ONLY want to catalog you movies, get Movie Collector (or DVD Profiler as an alternative)
If you want to catalog your movies so you can play them back via a PC/Touchscreen interface, then get DVDLobby (DVDLobby can also import data from DVD Profiler).