I just ditched cable this winter. The hardest part for me wasn't giving up cable, but the nice MythTV DVR PC I bought from components and installed when it still meant something to install your own Myth box. (Not really bragging, I'm just proud of my accomplishment. Ok, so yeah, I guess that means I'm bragging, so sue me.)
Now I have an old Mac mini with Boxee on it hooked up to the TV (36" LCD 720p, nothing special at all) and can control it all with an Apple remote, which I like. (Well, I have a BT keyboard/mouse if I want to browse to something not available as an app on Boxee.) I also moved my home media collection to a smaller, quiet PC that also serves as the home Samba share, in another room. Not that the myth box was loud, but now my living room is super quiet.
So far, I really haven't missed cable, and I'm quite happy with the setup.