I mostly use Google, it's been reliable for me.
Alternatives include Altavista which works with Yahoo and is a sloppy mess. There's Dogpile.com and Yandex.ru (although you may need to learn a new language, it's a Russian search, hit the Translate button and it works like a charm.) I like Yandex.
I've used Bing, don't like it.
There's also Blekko.com it's an interesting alternative.
Similar to many websites (including able2know) google is subject to making changes, which some view as good and some don't.
When a site changes, I try to put my mind in a place thinking of when I first came to the Internet and everything was alien. Back then I had Prodigy as my provider, they since then absorbed were with AT&T, I was gone from them by then. Anyway it all looked strange but I slowly adjusted, I try rye bread with a smidgen of mustard and liverwurst as a quick tide through.
Back to the original thought though, I use google most of the time. It's not my favorite appearance right now but it is still working.