I haven’t done enough of a comparison study to determine if Yahoo is a better search engine than Google.  So I can’t really answer the question.  I will say my gut tells me Google as Yahoo beat in most cases.

But I have had more success finding my own things with Yahoo much like others out there, as well as when it comes to Search Engine Optimization.

That doesn’t make Yahoo a better search engine, but it may make it better for certain types of searches.  If most of my most important searches are always found in the top 10 Google SERPs, then that is all I need.

What about Bing?  Same logic applies.