The points need to be highlighted at the time of tv purchasing-
1.video processing-How to know if a tv is not over processing a video..standard bluray to choose-Warrior, Green Zone, Gladiator.
There are many sequence in green zone and warrior which are grainy than others..so look if the video in your tv is exact what directors are intended to represent in those scenes.
In gladiator there are various close up shots of face..check if the skin is looking natural/crisp as it should be.
2.Color accuracy-Now there are a long list of blurays to choose from..
Saturated color-Transformers trilogy, Twilight..
A little bit less color(used in most darker movies)-Harry potter series from 3-7,Raven etc.
Natural color-Planet earth
No so good color- Jurassic park(bluray transfer is not great)
3.Black level-Dark knight.
4.Pic quality-You will not get same picture as theater by playing a bluray disc cause the data in theater use almost zero/very less compression where bluray uses high compression. So there is no point comparing these two picture qualities.
For a little example - when you play a br disc when there is a scene with varying same color like(dark red to light red)..you might see a very little color banding..where in theater you won't see any such thing..but if you try to encode it to lower size you will see color banding..why cause the information here is less hence the video processor represent it by band..but not smooth color gradient.