The Samsung F8500 is the brightest plasma TV ever, and is even able to challenge some LEDs. While its blacks don't beat plasmas from Panasonic (like the ST60), they are still very good. The only downside is the anti-glare filter produces some slight horizontal dark lines.
The F8500 has deep blacks and good detail in the shadows. However, it is about the same as the lower-end models from Samsung. Also, the Panasonic ST60 performs slightly better in a dark environment for a significantly lower price.
When setting the input type to PC, the input lag of the F8500 is very low.