I have the 42PX600U and love it. I looked at lots of reviews and think this HD set is the price/performance leader.
I found that the following settings online will get you the best picture quality for most sources (SD or HD):
Panasonic TH-42PX60U Optimal Picture Settings (ISF Calibration)
Picture Mode Standard
Picture +22
Brightness +8
Color -1
Tint -4
Sharpness -14
Color Temperature Warm
Enhanced Black Level Off
I found that the following settings online will get you the best picture quality for most sources (SD or HD):
Panasonic TH-42PX60U Optimal Picture Settings (ISF Calibration)
Picture Mode Standard
Picture +22
Brightness +8
Color -1
Tint -4
Sharpness -14
Color Temperature Warm
Enhanced Black Level Off