I've had a 40" Samsung LNT-4042H for 6 years. Last summer I got a Sony EX500, and on day 89/90 I returned it to Walmart because I couldn't deal with the flashlighting. This summer I tried a LG 55LM7600 (I'm on day 5/30 for Best Buy's return policy). I thought maybe flashlighting would be more controlled, and indeed many reviews on Amazon say they have zero flashlighting, but it is definitely apparent and distracting on my set. Some of my favorite movies are dark movies- Tron and Dark City, and I'm paying more attention to the dumb lighting bleed at the corners than the actual movie.
I'm at a loss when it comes to LED(except passive 3D, I might miss that), so I'm beginning to realize that I need a plasma. Either the Panasonic GT50 or ST50 in 55" or 60". I absolutely cannot wait to watch a movie with awesome blacks and zero light bleed.
The only thing I'm worried about is image retention. I wish TV stations didn't enforce a static HUD, but that is not the case. Sometimes I watch one channel for hours at a time, (Storage Wars on A&E, Animal Planet, History, Discovery, AMC... they all have HUD's).
How long can I watch one channel before I have to worry about image retention? This also applies to when I'm browsing on my desktop. I'm sure I can set a screen saver to come on often, but I'm still worried.
Also, how much better would the GT50's THX Day setting be watchable in daytime compared to just upping the brightness on the ST50?
Office - Onkyo 506, AV123 X-LS Encore Monitors
Living Room - Panasonic 60ST60, Onkyo 707, Ascend Acoustics Sierra-1 LCR
Car - Focal Flax 3-ways; Arc Audio KS 2500.1, 300.4, 300.2; Audison BitOne; Digital Designs 3515