Your best bet might be to find one via a colleague.
UPDATE Because I am not capable of creating an answer that meets SE Standards the first time and feel the need to be rude about it.
Why? Because most recruiters are a lot like used car salesmen. With experience, you will learn this. Your colleagues have likely interacted with recruiters, and it's possible that some of them have had a rare, good experience with someone. This is much more reliable than looking at ads in magazines, etc. There is no www.ethicalrecruiterswhoreallycareaboutyou.com
How? Simply ask your colleagues. "Hey Sally, can you recommend any good recruiters?"