I have a 60 inch Panasonic Plasma, second best one they make, would not go much lower in the line up.
Costco doesn't sell plasmas the last time I checked.
Like others have said, if you have windows which let in a lot of light and you do any daytime TV watching on the weekends go with a LCD.
Otherwise in a dark room plasma reigns supreme.
However to be appreciated sources like antenna TV and Blu-ray are best. In addition the LG LCD I have does a better job of automatically adjusting to the proper aspect ratio, the Panasonic plasma often requires me to push a button on the remote.
Some people get caught up in "features", and you will find more "features" on the LCD's, the money goes into the basics with plasmas.
My thread from a year ago"
http://www.whatsbestforum.com/showthread.php?7694-Panasonic-Plasma-TV-Product-Line-Up-Hierarchy
Now everyone is raving about
OLED's.
http://www.whatsbestforum.com/showthread.php?7694-Panasonic-Plasma-TV-Product-Line-Up-Hierarchy