As a base case - I have been using a Philips 170B2m for the last 6 months or so - it cost me £499 and is now down to £349. On paper it shouldn't be good for games or DVD (switch rate is 40 ms) but in fact it works excedingly well.
I'm not suggesting this is the best to go for - as I say, treat it as a base case. There are many faster and I am sure, better TFTs out there now. I like the look of the new Hercules but haven't seen many of the latest models.
I really think your best bet is to haunt PCW and other places with access to operating TFTs. Take a DVD with you or some other way of testing them out (a good salemen will always be willing to give you a demo if he / she smells a sale)
Probably too small for you but we have 3 Samsung 152T slimline TFT. Very good spec foo the price £210 on offer at simply. We tried one of the AOC 17" for ~£260 but it just wasn't as nice even though it was larger.
Don't want to highjack - as I am in the market for a snazzy TFT too - but has anyone considered an integrated TFT with TV tuner - I saw an 18inch LG or BenQ I think in John Lewis last week for about £550....