If I don't want to pay for a professional software, I try to find it's freeware counterpart. It was quite a challenge 10 years ago, when a free software would often be ugly, unstable, limited and poorly maintained, but this has changed, in great part thanks to the excellent Sourceforge community. Now there are many professional-grade open-source applications available and it became impossible for me to do without some of them.
To start my own best-of collection, the first application that comes to my mind is Ant Movie Catalog. While apparently not part of the Sourceforge listing, it's an good example of freeware that outperform by far any payware I know of.
It evolved to cover now every important aspects of a good media database: Easy and complete interface, powerful import/export functionality, powerfull scripts (constently updated but you can create yours) that allow you to grab the DVD cover and information from various specialised web sites, loan management (very important!), and last but not least,a highly configurable print-out interface.
Also, have a look at the other less popular software from the same author.