It would be wise to ask this question separately for 5.56 and 7.62. While some like KAC and Noveske are top notch in both calibers there are too many variables between the AR-15 and AR-10 style rifles to not get a single thread confused.
Also it would be best to describe your applications. If a highly reliable defensive carbine is primary then the obvious choices in 5.56 are Colt, BCM, Daniel Defense, Noveske, KAC, LMT, and others such as PSA, Spikes and Sionics. Out of the box or piecing together components, these are brands not to ignore.
The biggest issue with assembling an AR isn't so much getting the parts together right - it's getting the right parts together.
US Army 1966-69, VFW Life Member, Retired Geek
Last edited by Quentin; 09-28-2013 at 10:56 PM.