Some people rave about Sony kit, but in the 28" 100Hz flat tube range I think the picture quality is generally similar. Obviously not in the same league, but I got a 28" Akura from Sainsbury's for £229, although you can find one from the same factory at various prices depending on the brand/features.
www.unbeatable.co.uk are pretty good on price - they have the KV28LS60 for £634 inc vat - they have a *lot* of widescreen TVs on their site, well worth a dig around to see if there's something else you fancy. I think you can collect from their Crawley shop to save the £27.50 delivery - just noticed this makes them more expensive than dabs :-(
Gareth
PS. I have a sweet Sony VTX-S750U Sky Digibox waiting to go on ebay if you're interested!