Cheapest 42" 1080P Full HD I have seen. This looks like the same set that was badged up as Wharfedale previously.
If so, they are made by Vestel in turkey.
I have the 47" model and it hasn't missed a beat. Going to try one of thes as well.
This will also get you a £10 voucher.
Update £399 - Follow the sneaky Argos voucher deal explained below (which expires today 18th Nov) for this price.