is there a big difference 120hz and 240hz on led/ lcd tv

 120 hz vs. 240 hz.   240 hz tends to be a little bit weird looking! :-( It looks like somebody sliding a piece of paper along! and somethings slow down after fast scenes!   120 hz is alot better! However it does have the same effect but not even half as strong. and everythings the same speed!:-)Go 120 hz!!!!    When it comes to brands DO NOT! I REPEAT DO NOT BUY A SAMSUNG!!!!!!!!!!!!! EVERRRRR!!!!!!!!!! They always break after a few months!!!! And they over heat all the time! They can seriously BURN you!!!! Plus over time the picture gets worse!!!!! It gets really grainy! Get a Vizio! Thay have awesome picture! they're made in america! Not to mention the amazing price! and on top of that the 120 hz is the best! I have a 19" in my room (below) and it's the best! Oh and don't listen to people who say they are an 'off-brand' it's not true!!! Or sharp is O.K too but not as good of color! NO SAMSUNG!!!!!!!! but they make O.K Cell phones! Also LCD is way better then plasma!!!

When you start talking Vizio (low end tv) vs samsung (higher end, overpriced for the contrast ratio) it's obvious in that respect it's better to get a vizio, but if you want a good tv that's got a good set of features, you want a LG LCD LED 240 HZ...they make one series it comes in sizes 42 inches (!699$) 47 (1999) and 55 (2600-2999) depending where you look...by far the best...

For most people it's very difficult to see the impact that "faster" LCD sets have on picture quality. Countless hours have been spen in  AV labs watching various source material from 120Hz TVs and 240Hz models and it's really hard to detect any difference (it's hard to detect any difference between 120Hz and 60Hz models, too). To be clear, what is actually checked is the  motion-blur reduction and not the  dejudder processing, which smooths out motion and makes film-based material shot at 24fps look more video-like. When dejudder is engaged, you can easily spot its impact on the picture.

So all in all there is really no difference that the average human eye is going to be able to see unless it is on the price tag itself.

240 hz is not a tremendous difference compared to 120 hz-240hz tends to have a reduction in motion blur but to the naked eye it is a very duifficult thing to notice. If you are in the market for a TV at 120hz you will be getting a clear and vivid picture as well or at least you should be.Right now Samsung is leading in the 240hz  by using twin MEMC ( motion estimation motion compensation) chips to achieve a true 240hz refresh rate.

Before you can understand the differences you need to understand what Hz and refresh rate means.
Hertz (Hz) – Hertz is a a unit of frequency equal to one cycle per second
Refresh Rate – In televisions and monitors,refresh rate is the number of times the screen is redrawn in onesecond. It is expressed in hertz (Hz)
240Hz is supposed provide an improvement to 120 Hz. The difference is sort of difficult to detect. So no there is not a big difference that you can see between 120Hz and 240Hz because you can get great quality viewing with both. Reviews on both show that you can get goos quality picture from both. You will have to be really concentrating on it to see it, but why do that when you can enjoy the great experience.