It depends on what your requirements are for one. If you just want something that will go bang every time and not give much problem, you probably have as good of a chance with the typical brands as any other. Those would be DPMS, Bushmaster, Colt, Ruger and lots of others.
Colt will maintain it's value better than most, but some of the others offer models that are half the cost, or nearly so. If you want a free float barrel or some other features, the price also goes up. If accuracy is an issue, then that costs more too, or you might get lucky.
I believe the best thing you can do is make a list of what you want in an AR and then go shop the websites to see what is available at what price and go from there. I believe there are more good guns out there than bad.
