When the ambient light drops to domestic levels, the LCD will be the one looking grey and washed out.
It's weird, but LCD behaves totall differently in brightly lit rooms. I can't explain why, but it does.
However, chances are you're looking at an LCD monitor for your computer. If so, set your desktop to a plain black background, turn out the light and see for yourself what and LCD TV might look like.
Then look at it from the side and say 'wow, that looks horrible'.
Computer LCDs are generally very different from LCD televisions they typically have
much lower contrast ratios (worse black levels) aren't as bright, and have different (worse) screen coatings so they don't handle bright light nearly as well either.
Most new LCDs only look grey if you've got the lights down very low, or off. Even in moderate levels of ambient light, most new LCDs will look black.
Plasmas never look black (unless you are viewing highly contrasted material on-screen, which tricks your eyes) regardless of the light settings. In bright light, the glass screen causes them to look grey, and in a darkened room it shows off the greyness of the blacks. (though they are a darker grey than most LCDs)
They look quite dull and bland. The blacks were a grey-ish colour, similar to how yours look Nik, and I also found that the whites were very dull as well. The main thing that made me notice it was an advert for Sky, as the whites on the advert were very dull. Next to the two Plasmas were one of Panasonics LCDs, a 37LZD80 I think. The differences between the two were huge! After everything I had read about the Plasmas having better blacks, better colours and sharper images, the LCD looked easily the better! It had vibrant colours with a really crisp sharp image, with inky black blacks! I looked at the settings for the Plasmas and tried to get the blacks on them better (turning down the brightness etc) but nothing I did could make the blacks even close to what the LCD was producing and they stayed at their grey-ish colour.
There are three reasons why the whites on the Plasma looked dull. Firstly, they aren't as bright as LCDs. While the spec sheets may list a higher peak brightness, in actual real-world use they aren't as bright.
Secondly, the screen material/coatings aren't as good at handling ambient light as LCDs. Once Plasmas get brighter, they will be able to use black-tinted glass (as we saw with more recent CRTs) which should help improve things but I would be surprised if they ever get as good at handling bright rooms as an LCD.
Thirdly, Plasmas have power limiters. The more bright areas on-screen, the more power the Plasma uses. Once you get past a certain point, the display has to cut the brightness to keep the power consumption down. So while a small bright object on-screen might look very bright, a full white screen will be quite a lot dimmer. This isn't the case with LCD where the backlight is always on at the specified peak brightness, and the LCD panel then blocks the light from it to produce the desired image.
As for blacks, seem my posts above.
When it comes to colour reproduction, LCDs are generally better at producing bright, vivid, extremely saturated colours far more bright/saturated than they are supposed to be. This can be eye-catching in the stores though. Plasmas aren't as bright/vivid but look a lot more natural and a lot closer to how it's supposed to look.
When it comes to reproducing darker colours, LCDs start to fall apart a bit. Dark scenes often look desaturated/murky compared to Plasmas. (and it doesn't seem to be a result of the poorer black levels)
Neither technology is anywhere close to perfect yet, and both have a lot of improvements to be made. If you plan on viewing in a very dim/totally dark room, the choice is easy get a Plasma, especially a Pioneer if you can afford it. (they will have much darker black levels than anything else this year when viewed in a dark room)
If you are mostly going to be viewing in a bright room, or with reasonably bright lights on, you will probably get a better image from one of the newer LCDs. Personally I would recommend one of the higher-end Sonys if you want a more natural image, or Samsung if you just want something that pops and don't care about accuracy. (though they are getting better)
There are other things to factor in as well, but I would primarily base my decision on what is going to have the best contrast in my preferred viewing environment. As I tend to watch in a totally dark room, I would be leaning towards getting a Plasma, for example.