I don't have a TV, just a computer with a TV card and a large 28" monitor.
I have a Happauage TV Card that plugs in to the motherboard. The one I have has Dual Digital Receivers on a single card with single aerial input. This allows me to either record 2 channels at the same time
and watch something that I recorded in the past or watch one channel live and record another. I use the Vista Media Center Application with the Windows Media Centre remote. This also allows you to pause live TV, very handy when the call of nature comes during a long film on BBC
I can also format shift (using free add on software) the recordings made using Media Centre so they reduce in size and can play on my iPod or on my Laptop when I'm away, alternatively I can burn to DVD which is viewable in any DVD player. Although as with all video related things this is quite slow.
There is software that will also automatically take the adverts out of programs when you are watching them back so even ITV movies are uniterupted.
I also rip my DVDs to the Hard Drives (2x 1TBs) so if I want to watch a movie all I do is press play.
Another thing I can stream live TV over the internet using a free addon called WebGuide. This also allows me set a program to record over the web and also let me watch anything I have recorded on the computer (in set folders) again streamed over the internet.
Think of this as Sky+ on steroids.