In
 the last few years, Google has attained the ranking of the #1 search 
engine on the Net, and consistently stayed there. Users are attracted to
 its mammoth listings and ease of search; and with the launch of 
Google’s PPC program (Pay Per Click) business sites are utilizing it 
more and more as well to help them in the marketplace. 
Yahoo is a search engine,
subject directory,
 and web portal. Yahoo provides good search results powered by their own
 search engine database, along with many other Yahoo search options. 
 
 
 
It's Microsoft trying to take over the world again.  Bing is Microsoft's
 new Search Engine.  
Bing (formerly Live Search, Windows Live Search, and MSN Search) is a web search engine (advertised as a "decision engine") from Microsoft. Bing was unveiled by Microsoft CEO Steve Ballmer on May 28, 2009 at the All Things Digital conference in San Diego. It went fully online on June 3, 2009, with a preview version released on June 1, 2009.Notable changes include the listing of search suggestions as queries are entered and a list of related searches (called "Explore pane") based on semantic technology from Powerset that Microsoft purchased in 2008.
Answers.com
 is an innovative way to find answers on the Web, without searching for 
them. Instead of going to your favorite search engine and typing in a 
query, then sorting through various links to find the answer that you 
are looking for, Answers.com "displays quick, snapshot answers with 
concise, reliable information." Answers.com's tagline seems to sum this 
up: "the world's greatest encyclodictionalmanacapedia." 
 
 
Ask.com,
 or just Ask, is a crawler-based search engine with lots and lots of 
cool features. Ask also is the parent company of such notable Web 
destinations as Ask for Kids, Bloglines, and Teoma, which is the 
underlying search technology for Ask's search.