gui design - Best UI for filtered search with many filtering options as opposed to single text field

What UI provides the best user experience when searching using many filters as opposed to a single text input.

For example: I have 15 filters (all optional) that users can filter results by. The emphasis is on these filters, not a text search. What is the best way to display all these filters without being overwhelming and created a cluttered interface?

The only site that I've seen that has managed to do this decently is OKCupid, which allows the user to select, then customize, a specific filter from a list.