Xbox 360 4200 Live Points Card. Was £34.99.
* You can play with friends across the street or around the world on Xbox LIVE and extend your favourite games with add-ons like new songs, levels, characters and more.
* Plus you'll find hundreds of HD movies instantly from Zune Marketplace and live TV from Sky with Sky Player.
* Xbox LIVE 4200 Microsoft points can be used to download content from Xbox LIVE marketplace including, game add-ons, new songs, map packs, levels, characters and more.
* Theme packs and gamer pics.
* Xbox Live arcade and community games.
* Age recommendations vary by content of games.
* The user must have an Xbox Live account which requires a valid email address and a broadband connection.
Current selling price valid until 02/11/2010
So far this is the cheapest I can find. I'm still looking for cheaper though so I hope this helps some people. Ideal for those needing points for DLC for games like RDR (like the awesome Undead Nightmare DLC), Smackdown Vs Raw 20111 and Fable 3.
Also if you spend over £50 you get 3% Quidco too.