We put pretty much all our discretionary expenditure through our Tesco Credit Card and get (we think) a very good deal. 1% on every £1 spent, which is sent quarterly as vouchers - these can then be used to buy "Deals" at 4x their face value amount (i.e. spend £2000, get £20 of vouchers, exchange them for an £80 Tussauds Annual Pass).
We don't buy anything with the card that we wouldn't otherwise have bought and the "Deals", - the Tussauds Pass, magazine subscriptions, Eurotunnel tickets etc. - are likewise things which we would have bought anyway. Getting them at 75% off is a nice bonus !
Nick