www.whitetruffle.com is the best I've found so far.
It matches based on skills and a few other attributes (like location and whether you have a US visa.) I've talked to them, since this is a subject close to my heart and I'm curious, and they're planning on adding a more detailed questionnaire and a little machine learning.
Right now they're restricted to New York and the Bay Area and they're focused on engineering positions, mostly at startups. But they do a pretty darn good job. I'm on there, and I get a job offer every few weeks or so, many from excellent companies.