I'm probably late to this particular game, but the Disable JavaScript extension for Firefox is terrific.
It saves your preference per-site, and disabling JS instantly vanquishes paywalls, "subscribe to our newsletter" popups, and many other kinds of intrusive, worthless garbage.
@ieure
The process can vary a bit based on the browser you're using. Basically you click the ublock icon, click a JavaScript button, then refresh the page.
@Demosthenes I have it; the web wold be intolerable without an ad blocker. But I didn't know it could also block JS per-site.