Depends what you want. Sky is very expensive, but that is partly because they are really the only option if you want a variety of sports and entertainment that go beyond the usual plethora of rubbish channels.
Now TV, which is basically Sky offering their premium services as a sort of pay as you go (you buy "passes" for specific lengths of time), non-satellite option, might be worth looking at.
Freeview is free, but rubbish, BT Sport is good but .... just sport.