A recent Which? report showed that buying a cheaper or own-brand TV is often a false economy as their energy use is so high that over the lifetime of the TV, it will cost you hundreds of pounds more than a more expensive but energy efficient one.
All our TVs are Samsungs and the quality is fabulous.
Be aware, however, the thinner the TV, the worse the sound, even on an expensive model. If you go ultra-slim you will probably need a secondary pair of speakers to make the sound bearable. We have a top-of-the-range Samsung and the sound is adequate, and a mid-range Samsung and the sound is dreadful - like it is being played through someone's phone in the next room. We happened to have a sound-bar from a previous set-up and use that to supplement the audio.
If you are not bothered about ultra-slim, you will probably be able to pick up a bargain on an old-style slim TV (i.e the type that came out c. 5 years ago and have just been superseded by the ultra-thin ones). Most come with a stand in the form of a 'foot'.