Bang for the buck a good plasma TV will still out perform LCD in terms of picture quality, motion processing, black level detail, and color accuracy.
Burn in is less of a concern these days than it used to be, and most sets have some sort of feature built in to help resist it's effects. Typically these are either a pixel shift (it just runs while the TV is on and you never even notice) or if you notice an image starting to burn you can turn on a white screen to help even everything out. Plasmas can be a little more susceptible during the initial break in period so I would just pay attention for awhile. I wouldn't think AH would be a problem because all the looking around we do would cycle what pixels are being used fairly often. But some console games or FPS with a fixed HUD you may want to limit to a few hours at a time for awhile. IF you see something start to burn in, just turn on the white screen for awhile and it should go away. The only time I ever saw a burned in image on my Samsung plasma here at home was after watching the presidential debates last year which were on CNN for a couple hours straight w/out commercial interruption and all the stupid CNN graphics and logo started to burn a little. I turned on the white screen for awhile and it went away.
But that may be just the excuse a mom needs to get her kids out to mow the lawn or something.
To speak to a couple things that have come up in this thread, it is probably a good idea to make sure the contrast/brightness isn't cranked all the way up, this is typically done in retail show floors because we tend to see what is brightest as being "best". Plasmas used to consume a fair amount of power but that's not really the case anymore, in fact depending on models Samsung has some plasmas that don't consume that much more power than a LCD.
Pioneer did make a really nice TV, however they've gotten out of the TV game, you still may be able to find a 2009 model someplace but I don't believe they will be making anything new moving forward.