I bought a Toshiba 37C3030DB from Empire Direct. It is listed as £599. I found a 10% off voucher from www.offeroftheday.co.uk for Empire (this voucher isn't available at the moment - it seems to come and go) by searching for the Tosh on the Offeroftheday website. This got the price down to £539. I then used my Quidco account to go to the Empire Direct website and buy the TV. This netted me another £10 off the price. Total spent: £529. They also delivered it for free.
Not bad for a TV that gets 4 stars in this months magazine in the 37 inch Supertest.