This is a hard decision for most people, myself included as there are some good rifles out there that are close in price.
You have the Armalite AR-50, Serbu BFG, State Arms/Eastridge Gun Co. Shorty, Barrett M99, ALL of them will shoot MOA or better with quality ammo and the shooter doing his part. All of them have good quality control, good customer service and warranty from everything I've heard over the years.
It's mostly going to come down to which one YOU like!
Here's why I chose the AR-50 when I bought it almost 20 years ago:
1)Price, cost under $3,000.
2)Looks, thought it looked pretty good and had that massive muzzle brake on it.
3)Ergonomics, very simple to use and setup.
4)Aftermarket, plenty of parts out there for it.
5)Warranty and customer service, both are good.