[quote name='Lice']very true, 4 years and my grandfathers plasma needed to be replaced.
If your a gamer that plays games for 7 hours plus, or don't want to worry how long you can play a certain games go for lcd.
If you play for shorter periods of time and want to worry about leaving your plasma on a channel to long then go plasma.
Plasmas still have image retention and it can get bad. (Cue comment: "I play games and leave them on the menu paused for days straight") Great, you got a lucky set, but I have read many posts on Avs where people get some news ticker ghosted at the bottom and spend the next 3 hours watching a full screen nature show to get the pictured refreshed.
Now I know on high end LCD's they are pretty much equivalent to plasma screens, but not the case on these cheaper vizios. Im sure the LCD will probably blur more and have a bit of input lag (5ms vs. 8ms on the lcd). The plasma model also has a better contrast ratio :30,000:1 compared to 700:1.
Even though im a LCD fan, In this case I think I would recommend Plasma, but be warned to the cons.[/QUOTE]
Now the temporary image retention you mention does still occur for sure. It's just almost impossible to get permanent image retention that you can't get rid off by putting it on full screen show, or better yet using the screen cleaner in the menu (displays a bright white screen) to get rid of it faster.
So if that worries someone, or they just don't want the hassle, then yes stay away from plasma.
As for your grandfather, sounds like he got a bad set. Plus, 4 years ago (or more depending on how long ago he replaced it) plasma technology wasn't as good as it is today. 60,000 hours till half life at 8 hours a day comes to 7,500 days--or about 20.5 years before it reaches half original brightness.
So other than the temporary image retention concerns there's really no reason to avoid plasmas. Again, just go check someout and see what you think. For your price range I'd probably lean LCD. I'd trust a cheap LCD more than a cheap plasma. If you're in high school or college a cheap LCD is fine. If you're out, I suggest saving up for another 6 months and buying a quality LCD or plasma.