Image Retention (I.E. CRT and Plasma owners)
Image retention tends to be a byproduct of LCD displays where the LCD remains in a fixed position, holding a charge, after the display is turned off. This is different than what plasma and CRT can get which is properly called uneven phosphor wear - or burn-in. Burn-in, unlike image retention, is a permanent issue that can't be fully reversed, though newer displays offer some technologies to help reduce burn-in potential, or negative imaging which will more evenly wear the phosphors if burn-in becomes an issue.
Anyway, more on subject: It really depends on what size the TV is and the quality of the scaler that is built in, and what distance you will be viewing from. A 27" TV is pretty much dead on size you want at a 12' viewing distance for standard broadcast television. So, a 42" plasma/LCD may be a bit small at 12', but it will do a better job with SDTV. Likewise, a 37" LCD will do pretty well on size for SDTV, but is way to small, at 12' for HDTV viewing.
If you have ZERO interest in HDTV or DVD viewing, then I would likely go with a smaller EDTV... But, I would also keep in mind that color accuracy and proper scaling is incredibly important in getting the most out of your display.
