What is the best AR 15 out there?

I am in the market for an AR 15 and I just want one to have one. I don't really need one but I want one in my gun safe. I have looked at Bushmaster, Rock River, and Smith & Wesson. I will use this gun just too go out in the woods or range and shoot what I can. Price is a factor so Colt and Sig may be out. Looking for opinions and things to factor in and think about. Thanks for your help!