The "fake" look in LCD/LED sets is usually due to refresh rate issues. Important to keep in mind the two big issues in motion - frame rates and refresh rates.
Original 60hz LCD's suffered from jitter and motion lag. Watch a panorama camera sweep on an old LCD and almost everyone can notice it. Plasmas, due to the way in which they project images, suffer from almost no such lag due to refresh rates (under 2 milliseconds, that's where the 600hz subfield jargon comes from, true 1080p = 60fps/2milliseconds delay per pixel = 600hz subfield). LCD's can be as high as 13+milliseconds. So LCD's upped it to 120hz, and then introduced a backlight flash that essentially doubles that (kinda cheating) and now they call it 240hz. A few elite TV's I think even managed to go true 240hz and double that.
The problem comes when you throw in frame rates. For a plasma, you have no issue, so the only math you do is resolving a frame rate to a supported output. Movies are the biggest problem here. Most films come in 24 frames per second. TV's mostly refresh the screen 30/60/120 etc times per second. Very fancy tv's can accept 1080p/24 output from a Blu Ray player (if it supports outputting pure 1080p/24), but most are doing 3:2 pulldown. (24 fps * 5 = 120, 30 fps * 4 = 120, so you're turning 4 frames into 5, which means you repeat the 1st frame twice, second frame 3 times, third frame twice, fourth frame 3 times - you split them into pairs and you have your 5 frames).
3:2 pulldown is a feature you'll see listed on most TV's, high quality plasmas do this exceptionally well. Other material is usually upconverted to the tv's highest output - 1080i (interlaced, ie 30fps) material - tv doubles each frame for 1080p/60fps, etc. Complicating things is that some blu ray players and digital set top boxes will also monkey with the frame rate prior to outputting it. If you have a nice tv, always disable that stuff and let your tv handle it.
Back to LCD/LED's. Now you introduce these techniques of converting refresh rates on top of the math of converting frame rates... And the result is an effect that can make movies look like they were filmed with a hand-held camera - super smooth. Some people like it, others can't stand it. But for sports, it can be awesome. A 240hz top of the line LED playing showing a football game with a great feed is can have a "I'm right there watching it" look. Watching golf on my roommate's 55 inch top of the line Samsung LED was incredible.
Most videophile types will have one input on their LED for movies, set to zero smoothing and enabled 3:2 pulldown, and one input for sports that turns all the smoothing features on. Most average users I see simply leave on all the bells and whistles and get used to it. I will say that some cheaper sets stick the 120hz on the box and lack the hardware inside to actually be able to do all the processing - you get seconds of extreme jitter after extreme smoothness that, well, sucks. So avoid those.
If you mainly watch sports, have a bright room, want an ultra-thin bezel and a badass thin set and don't mind paying for it... LED is your ticket. If you're a movie buff, videophile, you don't mind a slightly less contemporary look and don't have sunlight pouring into you room - or if you want top-of-the-line picture quality for under $1,200 - Plasma is probably best for you.
And now I'm done with my super-nerd TV chat.