I've got a 58" Panasonic Plasma that is 12 years old and a 50" that is going on 15 and they are both still incredible 1080p displays. I also have a 60" Samsung LCD in the master bedroom, and while it is a great TV, it still doesn't give the image quality and viewing angle of the plasmas. I've never had one issue with the plasmas (and to be fair, no issue with the Samsung 60" either).
I was also given a dead Samsung 42" LCD that at the time was only about 4 years old. I fixed it with $2 of caps in the power supply and now have it hanging in the garage. Did that repair about 3 years ago and it's still going strong.
I think many new TV's are just a crap shoot. Decent quality and may last forever or you may get a couple years out of it before it dies. Since Panasonic no longer has Plasmas, my preference now are for the Samsung LCD's.