Got a proper HD TV (the husband bought it at Christmas - it's huge) and a HD box (ours was on it's last legs) - but honestly can't see the difference. Could be because the screen is always covered in sticky fingerprints or it could be my eyes on the fritz! But still not sure it's worth the money. You need to find a shop that has two TVs (an ordinary one and a HD one) next to each other so you can compare picture quality.
In the White Rose Shopping Centre near Leeds they used to have a HD demonstration where the screen was split in two, one half showing the picture in HD and the other half normal. I don't know if it is still there, but I must say that I was not impressed, and I have not gone onto HD for that reason.
don't forget - VAt is going to be going up again at the end of the year .... it's worth waiting until the Christmas sales where I am sure there will be some great pre-VAT hike bargains to be had!
many of the channels are over compressed meaning that the HD quality is lessened.
the better HD channels are BBC and the documentary channels such as Nat Geo and History.
Movies are ok but not mind blowing. If you flick between the std and high def channels you can see that the picture is sharper and more vibrant.
When I made the jump to a bigger screen the standard def picture was actually a step backwards as it is getting stretched that much larger. all HD does in most cases is take it back to where you were on a smaller screen if that makes sense!
Wait a while, if you have a good quality TV it's hard to tell the difference, we have HD but have to wait for 12mths to decide whether or not to cancel! It is an expensive package and something you can live without!