TFT display vs LED
Makers are extremely confusing with regards to marketing and advertising with this stuff, unfortunately, so it's maybe not a selection between TFT and LED.
The TFT bit is pretty unimportant as all modern TVs tend to be TFT-LCDs (really, or Plasma screens)
As Nanko states, the so-called LED TVs are called that since they have actually a backlight manufactured from LEDs. All mobile LCDs are like this but larger screens tended to have CCFL (fluorescent) lamps until recently.
LED backlights have less flicker and so are better than CCFLs but they are usually not rather as bright plus don't replicate tints rather along with the spectral range of light actually nearly as good on cheaper LEDs. Some TVs have backlights produced from Red, Green and Blue LEDs, normally referrred to as RGB LED TVs, which generally have better color reproduction than any various other TVs but they are more expensive.
Both CCFL and Light-emitting Diode TVs are side- or rear-lit. Edge-lit people may be thinner but may experience a little irregular brightness across the display. Rear-lit Light-emitting Diode displays can perform some clever tricks like neighborhood dimming to simply help improve black colored levels.