I have been a huge proponent of Readbility for a while now. It looks like they have gone from meta buttons to a full on Firefox addon now.
What does Readability do? It unclutters everything from the article you are reading: Banners, extra links, sidebars, ads, multimedia. What it leaves is a customizable set font and background so you can actually just read the damn article.
I love it and if you are like me you probably will too.