Google's search results are far from being flawless, but sometimes they're better than advertised. I was trying to find some information about an algorithm and Google returned a page from a book available online. I liked it so much that I almost read the entire book (mostly for the writing styles and the "war stories"). Last week, I searched for the title of a book and found a great short film inspired by the book.
Marissa Mayer said in an interview that many of the web pages available online wouldn't exist if we didn't have a good search engine. If nobody is able to find your web page, you'll have less visitors and your site will grow much slower (a lot of web sites receive most of the traffic from search engines).
I wonder if showing a list of great web pages not necessarily related to your query, but from the same domain, will help you understand a topic better. Google could provide an "exploratory" mode that expands your query and shows you more from the full picture, like zoom feature from Google Maps. Google already provides recommendations based on the choices of other users and has a log of your previous queries, so it could disambiguate your query, assign it a point in the big space of searches and show the most interesting results from the important queries that surround it.
Did you ever discover unexpectedly great things by searching with Google (or other search engine)?
{ link to Marissa's interview via Google Blogoscoped, that also tells the story of AdSense and Gmail's contextual ads }