Google Search Option I Would Like To See

Google search is great. However, more and more often, it is somewhat polluted by the predictable results:

• Wikipedia
• LinkedIn
• Facebook and LinkedIn imitators

I would like a search that gives me the top links for my search term, where the domains are outside the set of domains that frequently turn up as top domains for all searches. In other words, I want a way to get sites that are authoritative because they are specialists in the topic, not because they are the internet equivalent of mainstream media.