The actual problem with plasmas with games and astro is the static images and not the games or astro programs itself. If you play games, be careful of those permanent images like Health Bars or HUDs. For astro its those channel logos.

Burn-ins will always be the issue for plasmas, though its much improved lately. Just be careful during the 'early hours' of the TV and avoid static images.

Image Retention should be differentiated from burn-ins.