I have use Google, Yahoo, Excite, Alta Vista, etc.
With regards to the discussion here, the key difference is the user-friendliness, presentation and search methodology used.
Nowadays,I prefer using iBoogie. Check out
http://www.iboogie.com for a feel. The key with this search engine is its ease of use and the key point for me which is the organisation to sub-folders for quick search as against results in Yahoo & Google if results are not in the first page, it can get very trying. iBoogie uses as base existing search engines and organise the results.
Another search that uses the similar idea of sub-organisation is Clusty at
http://www.clusty.com
Check these out and if the results are better. I personally prefer iBoogie now - its fast and the folders are intuitive for quick search.
Best Rgds
Kevin Yeow