What do you think makes sites like this one freely available to everyone? Ad revenue. By blocking ads, you deprive the site you're visiting of its lifeblood.
I can see blocking things like doubleclick.net cookies and other insidious privacy-invading things some sites throw at you. And blocking pop-ups and pop-unders, as the site is doing something you didn't give them permission to do.
But blocking fixed ads on a web page/site that you find value in is basically stealing the site owner's band width without paying for it. If you don't like ads, that's fine, don't visit their site. Or send them a couple bucks to make up for the lost revenue.
Parallels between TV commercial skipping and ad blocking are non-arguments. TV commercials take time away from you; an ad banner does not.