If you are looking at the Sony for £3000 then also consider the Samsung SP46L5HX which is similar technology at a similar price but possibly a better TV overall. If you like the Samsung then consider its little brother the SP43L2HX which is only 3 inches smaller but about half the price (from
www.pantheronline.co.uk.) If you like that then also look at the LG RE-44SZ21RD which is in a similar price range to the smaller samsung.
You can search these forums on the different model numbers to see what people have said about them.
I was originally interested in the Samsung SP46L5HX but ended up ordering the Toshiba 51wh36. This is a much bigger and less convenient box to have in my living room, and I've had to buy a separate rack to store my AV components off to the side instead of on a shelf underneath as I could have done with a Samsung. What swayed me towards the Toshiba is that I wanted the best picture quality overall, and I'm told (in these forums) that as long as you are willing to spend hours fiddling with the settings, then the Toshibas superior ability to deal with dark scenes make it the better option overall. I suspect that except on dark scenes the Samsung would give a better picture (brighter, sharper) without the need for careful configuration. I was watching the Samsung in Currys, and even though it was mounted high on a wall with spotlight pointing directly at the screen, it was giving by far the best picture in the shop. The only time I started to doubt the picture quality is when the news cut to scenes of riots in Haiti and the scenes with black rioters showed up the problem LCD has with blacks.
Another important reason I eventually went for the Toshiba is that it gives an even bigger picture than the Samsung for half the price.
To answer your question, I think the 36" CRT will give the best picture, the other options will give a bigger but not quite as good picture. The CRT will be extremely bulky and heavy (relative to the picture size) compared to the others.