The best extension to do this is to run NoScript in temp whitelist only mode. Every time you visit a crappy website with lots of JS domains that load JS domains

The best extension to do this is to run NoScript in temp whitelist only mode. Every time you visit a crappy website with lots of JS domains that load JS domains that load JS domains you'll have to spend 20 seconds load and reloading the page till you get it to work. If at all. It thoroughly discourages visiting these bad websites. But good websites (ie, not web apps) will load instantly and unimpeaded. And as a side effect you're protected from most browser exploits since the vast majority require executing JS.