Google has quickly become my favorite search engine - by far. It is easy to use, quick, and has many features. It also has spell check (for a search), and NO advertisements! The image search feature is also top notch.

Special Features:
type "site: [anysite.com]" to search a specific site
type in any phone number to see who it belongs to
type an address to automatically return a map

Runners Up:

2.
    - searches the most pages of all - even more than google

3.
    - not only search the web, but images, audio, video, etc.

4.
    - no ads, nice layout, quick

5.
    - cool question search format