This is my "hosts" file. I've never seen any popups/popunders on IMDB while using it. It pretty much bans most of the Internet
DISCLAIMER: Use it at your own discretion and backup previous "hosts" file just in case you won't be able to get your daily dose of pr0n anymore. Might require restart of a system (not sure) and/or browser (sure).
I also have a shortcut pointing to %windir%\system32\notepad.exe "%SystemRoot%\system32\drivers\etc\hosts"
in "Administrative Tools" that comes in handy once in a while I come across sites that link to anything I don't want to see in my browser. Usually, it just takes a moment to find a domain name of such linked content if you glimpse through the pages HTML code. BTW, some sites block viewing of source code in browsers (like this site) but you can still view it in some HTML editors (just open the sites address in it and it should retrieve any HTTP response)
Once you get to know your enemies, simply add them to this "hosts" file and restart your browser.