Give a list of top search engine user-agents

List of top search engine user-agents

A regular visit by search engine robots like Googlebot, yahoo slurp etc is a good sign,

Here is the list of top search engines crawlers,

Googlebot/2.*ooglebot@googlebot.com)
Yahoo – Yahoo Slurp
Msn – Msnbot
Lycos – Lycos_Spider_(T-Rex)/3.
Teoma- Mozilla/2.0 (compatible; Ask Jeeves/Teoma)