For gaming, I always say go with an LCD, because there's always the risk of burn-in with plasma. It is inherent of the technology and cannot be completely eliminated. Don't let anyone tell you otherwise.
That said, when talking about LCD, my advice is also always the same... Sony. Their displays have the most (out of the box) natural looking picture of any LCD you will find. Samsung usually lists a deeper black level on their spec sheets, but Samsungs tend
to lose detail in dark areas, which end up looking like black blobs.
I haven't checked Wally-World in a long time (I wouldn't buy a TV there anyway), but from what I've seen, what they display as their top of the line merchandise is usually that manufacturer's upper entry level or mid range line. The salesman may tell you
This is the best set (brand X) makes, when in reality, it's only the best they carry. When the TVs actually are a manufacturer's upper level line, they are usually last year's models. Again, this is just what I've observed in the past. It may no longer
be the case.
You may want to check what http://www.crutchfield.com has to offer. Their prices are usually MSRP, but they often have great deals. For instance, when I purchased my display, it listed for $2500.
They had it on-sale for $1800 with an additional $400 off with the accompanying purchase of a Sony BD player. I picked out a player that was on-sale for $300 & took $400 more off the TV. All tolled, I got the ($2500 list) TV & ($400 list) Blu-ray player for
$1700. Plus I paid no tax or shipping.