I enjoy the free programming Comedy Central puts online. Shows like the Daily Show are cut up into clips, so you can't watch a whole episode straight, but most (all?) of the show content is available. The site has some ads, but using firefox and adblock seems to bypass them.
With ABC's free-shows-with-ads-the-morning-after and DVD sets coming out sooner after seasons end, paying $35+ for a low quality, heavily restricted copy from iTMS doesn't appeal to me at all.