There are quite a few limitations on the free apps, but there's a great one out there called TV Shows Stream. It costs about $4, but it is well worth the money. You can try it out for free with the lite version, but it only lets you watch a couple shows before cutting you off.
It streams flawlessly through a wifi connections, but over a 3G connection it sometimes needs to buffer the shows. It's by far the best app that I've found for shows, so give it a try and let me know.
-Anonymous