Be careful, a lot are advertised as twim tuner but you can only record freeview and watch analogue. I've got 3 now and they all work very differently, check out the timeshift function as that's what you'll use most. My Phillips is best at this and the SONY is rubbish, shame as the Phillips is broken (why I have 3).
If you buy one with a DVD burner you can archive anything you want to keep.