Duck electricals are currently selling this TV at the lowest web price of £550 + £20 delivery. This is the freeview less version of this popular TV, but if you have Sky or cable this doesn't matter. It's also far cheaper to add an external freeview box anyway.
Go through Quidco where cashback on this is quoted at 4%, although the current figure is unknown.
Once on the site enter the code ZYQP at the checkout to get 10% off. After entering you payment details the price will be shown as £495 + £20 delivery. I've been holding off buying this TV until i could get it for around £500 - now finally took the plunge!
Code definately still works as of 7th Jan.