I google, google, google all day long. Hubby and son are Yahoo fans, but I'm a googler from the word go.
Why? couple reasons. They find stuff, especially tiny phrases that I remember from something I read two days ago... really well and really fast.
Secondly, I like that they are A SEARCH ENGINE first and foremost. I use the Google taskbar mostly, but if I do go to their homepage, what does it expect me to do... SEARCH. Yahoo wants to tell me 10 signs my guy is cheating and 5 foods I should eat and ... you get the idea.
In your browser, the search engine at the end of the URL, what do you use and why?
Google
Yahoo!
Wikipedia
eBay
Package Search (for linux)
Other? If so, what?

Chowhound
Comic Vine
GameFAQs
GameSpot
Giant Bomb
TechRepublic