I've been using AV as my default se now since last fall. I've tried using others, but for the sake of general searches, I don't think AV can be beat. I don't think there is another engine even close to what they are doing.
If I had to rank the se's by current relevant results:
1: AV. Extremely low spam ratio now. Results are very tight to the search. My only beef is as a search gets more complicated with more keywords, the results can stray all over the place. AV tends to fixate on one popular keyword in the search and return results from that word instead of the whole search string.
Such as; earlier I was searching for "microsoft windows 98 tooltip tweaks fixes". AV just couldn't get past the "microsoft windows" in the search string and return any results related to tooltips.
2: Pure Ink (Iwon). Hmmm. I like Ink, and this is as good as it gets.
3: Infoseek (yes). when used with the 'search within results', it is quite accurate. Unlike AV, when you drill down with more complicated searches, results become very accurate. When I couldn't find any info on my tooltips search, I went to Infoseek and drilled right down to it with search within these results.
4: Fast/AllTheWeb. A touch spammy in places, but I find their result to be a close gauge of reality.
5: Excite. Their new results are pretty good. I really like the new low key layout.
6: Lycos. Although it is rerolled Fast, it is still good.
7: Google. I don't get it. Rarely have I found anything I was looking for at Google. 9 out of 10 searches fail in frustration at the impossible task deciphing the results. The most over hyped engine I've seen. They simply don't deliver the results.
8: The also rans: Hotbot,MSN,Direct *hit, etal.