Best thread ever!! I registered just to comment (though I've lurked here before to research this very issue). This is EXACTLY what I'm going through (minus the actual purchase).
My story is I first encountered this problem when my friend bought a new TV about 3 years ago (not sure what model) and we played Guitar Hero. I'm pretty good at it but on his TV I freaking
sucked. It
killed the fun when it's almost an eighth note off the beat. And I'm almost unable to play off the beat (opposite problem of some people I suppose). Nobody else noticed which ASTOUNDED me because it is SO FREAKING OBVIOUS, but oh well. Must be nice to live in such oblivion.

So I went to Fry's electronics about a year and a half ago and looked at all sorts of TVs, keeping input lag in mind. I'll be pissed if my foray into HDTV's means I have to sacrifice gaming. Because with input lag, gaming just feels disconnected. It's no fun. I was at first sure I wanted a plasma since at the time they just looked better (LED TV's were ridiculously expensive then. I can't believe how quickly they came down in price). But then I read about IR, and I have my media center PC hooked up to my TV, which makes for a nice Tivo equivalent except I have 2 TB of storage

I can also toss my DVD player and don't need a separate BluRay player either. Anyway, add in the fragility of plasma (I've heard if you are moving you have to be really careful it stays absolutely vertical), and the extra energy costs, and the weight...so I started to swing LCD.
But I actually brought in my PS2 to the store and hooked it up, and again the lag was TERRIBLE! In GameMode on the Samsung I tried (which had a nice picture otherwise), the lag was ... better ... but still really annoying. And the picture looked like $#%@. In Metal Gear Solid it looked decent until you moved the camera. Then everything lost all focus and got all blurry until you stopped moving, then it was okay again. But even so, the GameMode was 480p resolution and unlike the non-GameMode mode, the picture looked awful. I was going to drop $1200 for
that?? Pass.
Now I'm again looking into it, but I'm really shy of pulling the trigger and buying a TV because I'm so afraid I'll regret it - mostly due to gaming input lag. Also a little afraid of standard def. content looking crappy, but that's another issue....
I'm driving myself NUTS looking for a TV, but I don't want to be stuck with something I don't like. Once I purchase something, I tend to hold onto it until it dies.
SO. I'm now looking at the Samsung UN46C6300SFXZA LED TV at BestBuy for $1200. But (I'm almost done here, promise), then I talked to a friend, and he gushed about Panasonic's plasma TVs, and now I'm swinging towards getting a plasma again. That was my original instinct, and despite all of LEDs advantages, the picture on plasma...it just looks
better. At least it sure used to a year and a half ago. I might be out of date now. It's impossible to tell in the store - they are all hooked up to a lousy daisy chained feed with messed up color & contrast settings and so many images and commercials flash by that you're lucky if you walk out of there without having a seizure.
Anyway, bottom line is: I'm looking for a 46" TV that will rock my world, without me having to sacrifice the enjoyment of a good video game. And I'm still confused about that Samsung. It looked super-sharp, and ridiculously bright, but everything also looked really fake. I mean, I like a little saturated colors - I'm not the type that needs 100% accurate color reproduction - but that TV was ridiculous. I hope it's just the calibration.
DarkestRed - I can't wait to see what you think! Thank you very much for starting this thread. If anyone has other suggestions for 46" TVs, I'm all ears, because I can't take any more researching, researching, researching. It's been 2 years on & off and I'm almost at the point where I just want to buy something - ANYTHING - to get it over with. But now I can hold off just a little longer

Looking forward to hearing your input and feedback! gl!