If that is your budget, here are your best choices as I see them.
BCM
Noveske
Colt
LMT
LWRC
POF
Not in any particular order. Colt makes a very nice AR. They are considered the best production model, with all of the little features that aficionados consider mandatory for a long lasting, reliable AR.
All these little things are just that; little things. They add up, though, and are important if you are spending that kind of money.
Things like staking, barrel steel, finish, bolt steel, various tests, and things of that nature. It may all look the same on a cheaper model, and it may not make a big difference to a soda can either way, but if you want to pay for quality, make sure you are getting it.
BCM is Bravo Company's house brand for their parts, and their stuff is top notch. You can grab an upper and a lower from them and have a complete rifle, in almost any configuration you want, and it will be top shelf equipment. Assembly is as simple as pushing two pins, if you want, or you can assemble the stuff yourself.
Noveske uses good parts, and the rifles are in high demand. Very good stuff.
LMT makes a great quality, reliable firearm, and I'd place them alongside Colt, on most things.
POF and LWRC are top quality, but like Knight's, they aren't always the same as other options. They are innovators at times, and well worth it of you are interested in that. Personally, I'd rather have complete compatibility with other parts.
Off the shelf, go with that Colt or LMT. Get a base model, so you aren't removing expensive accessories when your mood changes. Grab the flat top upper, so you can fit other accessories down the line. You can get a rail-attachable carry handle, if you like the looks of it.
BCM is the new darling of the AR world, though. Their stuff is wonderful in that price range. And, with their new hammer-forged barrels.... Well... You just can't go wrong.
RRA, Stag, DPMS and things of that nature are decent rifles, but they aren't in the same class with the others. Bushmaster, Olympic, Armalite, and the lot are fine for plinking, and will save you a bunch of money, but they again aren't in the same category.
For 1700 bucks, you can have really, really good stuff.
My personal opinion, and that is precisely what it is, a personal opinion, is that if you want a plain jane rifle, go with the Colt. If you want something for your zombie invasion, go straight to Brasvo Company and start picking out cool uppers and lowers.
If you just want to have fun plinking, though, it doesn't really matter what you buy.
You can have fun without spending much money, but with your budget, you may as well get something nice. Colt or BCM would be my vote.