UPDATE - This pre-order Gran Turismo 5 deal from Amazon has now ended, but you can find all the best prices here on the price comparison page.
I've just seen this thread on Hotukdeals, and it already has 257 comments, and 1854 degrees of heat, in the 3 short hours since it was posted. It's a pre-order for Gran Turismo 5 for the Playstation 3, and the price is only £17.59. The PS3 game is due to be released on the 4th of December 2009.
According to a price comparison, Gran Turismo 5 is selling for £32+ at most other stores! It's worth noting that Amazon have a Pre-order Price Guarantee which states the following:
Whenever you pre-order a book, CD, video, DVD, software, or video game, the price you pay will be the lowest price offered by Amazon.co.uk between the time you placed your order and up to and including the release date.
Of course they can probably just cancel all orders if they don't feel like fulfilling them.
So, even if the order runs the risk of being cancelled, it is still worth pre-ordering a copy on the off chance that Amazon will actually fulfil their pre-order promise. Fingers crossed for the PS3 owners!
Thanks to doofenshc!