Windam Weaponry M4: budsgunshop.com/catalog/product_info.php/cPath/2084_36_1989/products_id/716007522/WW+MPC+223REM+16+M4+NO+CARRY+HANDLE+TELE+STOCK />You can't beat that quality at that price point. You can get a similar gun from Del-Ton for $100 less, but the Windham option is a huge step up in quality (that's where all of the competent people from Bushmaster went after the Freedom Group buyout).

Your best bet is a cheaper model. They are just as good as the real expensive model and are not part specific. Most of your top dollar ar rifles are not any better than your cheaper ones. I would not buy a smith or a ruger as they are both part specific, meaning that they take special parts and their parts will not interchange like the other guns. As far as specific model I would go with a palmetto, windham, dpms, bushmaster, Again as far as accuracy all model ar rifle are fairly close. Again I would recommend a cheaper version and definitely would not get a smith or ruger. I think for the money your going to spend, I would recommend the dpms. Best bet for your money and not part specific. Hope this helps