The best value for your money is one of the Rock River Operator 2 series. If you can afford to spend $1000, you won't find a better shooter with more bells and whistles under $1500. I just picked up the Tactical Operator 2 for $1000 OTD a few months ago, and I'm surprised the sale is still going on. My local gun shop only gets 1 or 2 in per month but can't keep them in stock more than a day or two before they're sold. The RRA 2-stage trigger is amazing, and you get a chrome bolt carrier group, high-quality barrel, quad rail, flip up front sight, etc. etc.
http://www.rockriverarms.com/index.cfm?fuseaction=category.display&category_id=461The only thing I don't like about it is the 1:9 barrel twist, which is pretty standard. But when I originally got in the market for an AR, I really wanted to get a 1:8 or 1:7 so I could shoot the heavier bullets. But most of the sub-$1500 ARs are 1:9 because that shoots the 55 grains really well, and the 42 or 72 grain bullets pretty well. If you go to the 1:7, you totally give up on lighter bullets, and the 1:12 will not be any good at all for the heavier rounds. Since I'm killing paper with 55-grain bullets 99% of the time, it wasn't a big deal to settle on the 1:9.