Other than the usual Google, Bing, DuckDuckGo, Yandex, etc., here's a list of search engines that are remarkable:
Interesting meta search engines:
* sweetsearch.com (for students)
Also, you should probably look up distributed search engines, peer-to-peer search engines, decentralized search engines, custom search engines, etc. These could in theory be great, but I don't know of any actual search engines of these types that you can just go to a website and use (or download and use), without having to do more than you're bargaining for.