Google - most of the time, give me a more results to look at
Yahoo - 2nd most of the time, also I use this to compare with the result from Google
MSN - hardly, very very rarely
Alta-Vista - very very very very very rarely
Alexa - never
I have already posted somewhere about this. These three major search engines Google, Yahoo and Bing are special for different purpose. Google gives better global search results, Yahoo has many portals so it gives local results better and Bing is better for Image searches. Google is accurate overall.
bing is smaller than google , it loads faster than google. But for me , Google is still the best when you search for information, solutions, technical issues etc.