The gas grill world is actually fairly regional. You're in SoCal IIRC which is a good thing, lots of manufacturers. Cal-Flame leaps to mind.
Also, if I remember your location correctly from reading it off your post header two minutes ago -- you're in a Barbeques Galore area. A few years ago I could vouch for them, but they've been through a few reorganizations and made some strange moves. Nevertheless, they sell good product at decent prices. The store managers used to have authority to negotiate prices -- I'm not sure if they still do. They're pretty good with after-sale service, which is a big deal.
It's been awhile since I researched the market, and longer still since I've been in it. It used to be common practice for fairly prestigious manufacturers to license their name to Chinese manufacturers who contracted directly with big boxes like Lowes, Home Depot, etc. I think it's still happening, but not quite as insidiously. That is a lot of grills come from China -- period. It's not the scandal it used to be.
Still, the problem with buying from Costco, HD and Lowes is parts availability after a couple of years. They sell some good grills. But you want to protect yourself against the occasional parts failure -- especially with a good grill. I'm not saying "don't do it." I'm saying "see what you can find out about parts."
In terms of longevity -- all the manufacturers have learned the lesson of using decent stainless of an adequate guage and using decent materials for the burners. The differences between less good and better are harder to spot; they're like fasteners, valves, plumbing, and so on. Speaking of fasteners, if you don't like whatever comes in the box, don't be afraid to run to the stove and replace it with marine or aircraft grade -- or whatever meets your standards.
It's been a couple of years since I looked, but Kenmore (Sears) used to represent solid value at the lower end of the good grill price spectrum. Worth checking out.
Not to be too obvious, but there's always Weber. Webers are good grills for the money -- borderline excellent. Well built, good features, good support, parts availability all over the country for years and years, you name it. If you're having trouble making up your mind, just consider Weber the can't-go-wrong default.