Google is, for the moment, pretty unique as it uses page rank to weight its findings, i.e. all pages have a certain "value", and the more they are linked too by high value pages, the higher they will appear in the results list. This means you generally get "more important" pages first, but if you're looking for something obscure on a certain subject it can become a wee bit tedious. Also, when Google sends out its crawlers to gather information it saves the actual html of a page so that you'll get the information faster. A lot of search engines base their searches on just the first few lines of a page.
Altavista is perhaps the most comprehensive search engine, but it is definitely suffering due to competition from Google.
Google doesn't deal with pictures though, I don't think, so a search for images won't yield much useful info.
(p.s. I'm not addicted to search engines, I just did my MSc dissertation on them.)