I could write a dissertation on this topic since it's related to my job.
The best non-Google, non-meta engines IMO:
1)
TEOMA - If they had a bigger index and fresher content (i.e., a more active spider that crawled sites as often as Google's spider) it wouldn't even be close IMO. Great engine. It just lacks in index size unfortunately. It heavily relies on link popularity like Google does, but it also does a better job of ignoring spam by the way it logically groups sites into subject areas giving those much more credence than links from sites that seem to be outside those subject areas. In essence, quality over quantity (although Google gives some credence to quality too.) If you'll notice, it's the only major engine that didn't fall for the 'miserable failure' Google-bombing tactic.
2)
FAST (aka alltheweb.com) - Still a great engine based off a very strong algorithm and a giant, Google-sized index. Yahoo owns this engine as well as AltaVista and the behind-the-scenes engine Inktomi. Since Yahoo is using Inktomi once they drop Google and only borrowing ideas from FAST this one has been pretty stale lately. It does a better job of Google though (IMO) of analyzing on-page/site content while still accounting for link popularity. But it's all but dead now unfortunately.
3)
INKTOMI - This one's been pretty volatile lately as Yahoo continues to tweak its algorithm. But its huge index should keep it very competitive with Google. Very similar algorithm and results to FAST. MSN just recently switched to using this service entirely (along with a few paid results at the top) and Yahoo will be switching to it VERY soon.
4)
WISENUT - This one had more even promise than Teoma at one point. Even with a MUCH smaller index at the time (late 2002) it served up results as strong if not stronger than Google (IMO) during Google's peak. Then LookSmart bought it out. It's still a great core engine, but has tiny index in comparison to the others.
Google's had a great run and will likely still have a great run for the forseeable future, especially with all the media attention its IPO will get. But the fact of the matter is that the biggest thing that made Google great, its pure search results, are no longer head and shoulders above most of the other major search engines. People were just so in love with Google during the past 3-4 years that they haven't bothered to look around to see that others have learned from what Google is doing (and in some cases have improved upon it.)
It'll be interesting to see what happens at Yahoo once they ditch Google in the coming weeks. Will people abandon Yahoo in droves? Or will they even notice? Just a guess, but I think there will be more of the latter.
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