Here's the first one that I ever heard of: http://www.bing-vs-google.com/
If you don't want to have to decide who's best, you can always use http://www.dogpile.com/ which brings results from all of the big ones together at once.
Interesting link. Tried it on a bunch of obscure things I would normally search for and google wins hands down!
Personally I hope google manages to get apple off its duff and fix everything I have issue with on the iphone (mainly apple policies and I want to choose what best for me)
If the next os (or next phone) isn't earth shattering I will be heading to android.