Spend £2,000 on the Amex Nectar card in the first three months, and you'll get 20,000 points. These are worth around £100 and can be spent on anything in the Nectar catalogue.
There's an annual £25 fee, but it's waived in the first year. Diarise when the year is up and cancel the card.
You'll earn 2 Nectar points per £1 spent on the card, and 4 points per £1 spent in Nectar partner shops (Sainsbury's BP & more).
Most retailers give 0.5p per point when you redeem, but some give 1p per point, making this freebie worth £200 at theme parks Legoland, Alton Towers, Thorpe Park etc. (read Loyalty Schemes for ways to max these).
Make sure you repay IN FULL every month or you'll pay 22.9% interest.
In order to qualify for the introductory bonus, you can't have held any of the following American Express cards within the past 24 months: Platinum Cashback, Platinum Cashback Everyday, Platinum, BA Amex, BA Premium Plus, Preferred Rewards Gold, Starwood Preferred Guest, Amex Nectar, Amex Rewards/Low Rate/Purchases