LED is definitely the best among the 3. Only main consideration is the price. Noticeable diff cos of the newer technology. If you're not a TV addict or use it for other things, I'd suggest save the $ and get plasma or LCD. In fact, sometimes, I find LEDs to be too sharp. Tire eyes easily.
It's quite irritating also that for the bigger sized ones, LED TVs tend to come with 3D capability which jacks up the price a lot more. IMHO, 3D is not worth getting. Not for now at least.