It doesn't make any odds on an LCD TV. With a CRT display, and an analogue signal, the picture used to be refreshed in real time as the signal arrived and was processed. The PAL system used 25 frames per second, but in fact delivered half a frame at a time (interlacing), so each half frame took 1/50 of a second to be displayed (50Hz). The electron beam would excite the dots on the screen, and as soon as it had passed, the dots would start to fade, so the screen would be flickering at 50 Hz. By storing the frames as they arrived, it was possible to double the rate at which the screen was scanned (essentially it just meant refreshing the screen with exactly the same information). The faster the flickering, the less visible it is to the eye, so this had two effects: less apparent flicker, and brighter picture.
The pixels on an LCD only change when "told to" so there is no fading between scans, consequently the only reason for refreshing the screen is to show changes in the frame. Therefore the refresh rate only needs to be as fast as the frame rate (or double the frame rate for an interlaced signal. For analogue PAL that means 50 Hz, and for HDTV, it's usually (I think) 24 or 25 fps.