Search engines worth identifying in an analytics program

[fischermx]

I'm creating a small web analytics software, and I wonder which Search Engine do you think worth be identified in reports.
So far, I had Google, Yahoo and MSN, now Live.
But also, I added:
AOL
Ask
Altavista
Lycos
AllTheWeb
Mamma

What else?

[encyclo]

You're missing Ask (Jeeves), which is one of the more significant minor players. Alexa should probably have a place too. For the rest, it depends on the market - if you have users in China, then you'll need Baidu, maybe Exalead for France. You should also distinguish the AdSense bot from the regular Googlebot, as well as have logic for handling the RSS feed bots such as Bloglines, YahooSeeker, etc.