I thought RSS feeds were a way to strip out the style and cruft of typical websites and package the content into a usable, accessible form.  Unfortunately and inevitably, feeds are littered with ads and other crap.  The best way I know of to simply block ads from websites is the Adblock extension for Firefox (sorry IE users; there's probably something similar for you too).  In addition to blocking standard ad services like doubleclick.net and tribalfusion.com, you can also block RSS-specific ad systems like pheedo.com and googleadservices.com.  And with Adblock's wildcard filtering method, you can block more advanced things, like anything from FeedBurner.  Here's a simple set of blocks that gets rid of all the stuff at the bottom of FeedBurner feeds: 
feeds.*.*/~a/
feeds.*.*/~f/
feeds.*.*/~r/
That way it'll block stuff whether it's from feeds.feedburner.com or feeds.someotherdomain.com. 

My apologies to anyone trying to make money through RSS feed advertising.  In the same way I can fast forward through commercials with recorded TV, I can prevent ads from loading on my computer.  Find a different way to make money.  Or keep depending on the people who don't know how to block it. #entertainment