Everyone knows Colt's Manufacturing is the Prancing Pony. Anderson Arms is the Poverty Pony. Better than no AR at all, and it can be upgraded as more funds become available.
I also would suggest Aero Precision, since their M4E1 Lower Receiver and M4E1 Enhanced Upper are what I would start with if I was building a new AR. I might even buy a whole rifle from them, or a complete upper and complete lower, and call it a day. It doesn't need to be upgraded, and is as close to "ideal" for multiple users and uses as I've seen in a "premium quality" AR at a reasonable price. An M4E1 PRO RIFLE 16" is $1,999.99 MSRP. I don't know what makes the PRO so special, but sometimes you can get an upper and lower on sale for a total of $700 or so.