I quite like Marginalia. I don't often find what I was originally searching for, but I still open 2 or 3 pages and find new websites with cool recipes or a new RSS feed to follow.
More than anything, it made me realise that there is still good stuff out there on the web. The old web is still out there - we just need better ways of stumbling upon it. I like the idea of having specialised search engines like this, dedicated to a particular vibe or corner of the web, and not trying to be everything to everyone.