Where can I download DRM-free TV shows legally?

[any ANONYMOUS forum user]

I'd like to be able to download tv shows to keep and watch offline.

I know that I can download some shows from the iPlayer on the BBC website, but they delete themselves within a week. I want to be able to download tv shows like Brothers and Sisters and Family guy, and keep them on disk. I'm very happy to pay for them, but it's important that it's DRM free.

Everyone I know has resorted to illegally downloading TV shows because they can't find any decent download sites. I don't want to do this, but there really doesn't seem to be any alternative in the UK.

Please can somebody recommend a good download site or program that isn't iTunes (It's not compatible with my computer) ?