The best search engine in the world in my opinion. Powerful and useful, it can find almost everything. No, Google does not have adult content. Only the sites that you can find by using Google have. It does not have viruses, illegal, violent, hateful or malicious content. No annoying ads or popups, no scam, fraud phishing.
Google does track all your searches BUT did you know that this is actually being put to very good use?
The CDC has been using google searches on terms related to "the flu" "influenza" "flu cures" "sick with the flu" and so on to actually predict flu outbreaks.
Using google tracking, the CDC has been able to see HUGE leaps in these search terms before people even end up in the hospital. It's been extremely useful for hospitals and doctors so they can anticipate a major flu outbreak before it happens and make sure they are ready to take in several sick people.
Many people scorn google's tracking, but it has been put to very good use. I can imagine that many other good things could come out of it as well.
I used to use excite.com and webcrawler, and eventually yahoo.com to do all my searching. Now my homepage is google.com
Google tracks and compiles vast amounts of information about your viewing habits. They do it by the obvious capture of your searches, but also a huge number of sites use the free "google analytics" to get their site statistics -- which also gives Google detailed tracking data that can actually re-create the page by page click patterns you have even though you're not on Google's site.