BBC IPlayer, this one allows you to watch upto 7 days old BBC programmes and each programme downloaded and unopen has about one month expiry, whereas once they are open there is only 7 days expiry.

Channel 4 on Demand, this one allows you to watch upto 30 days old Channel 4 programmes and each programme downloaded and unopen has about one month expiry, and again once they are open there is only 7 days expiry.

Joost, programmes here do not expire and they can be viewed when available. Although this is different from 4oD or IPlayer since it does not have a terrestrial counterpart.
So I suppose even I do not have a TV now, there is still loads to watch (when I am not working obviously kakakaka)