AR wise I have Ruger SR556, Colt 6724 and a DPMS SBR that I have a couple of different Uppers for.
The Colt 6724 will shoot sub MOA.
THE SR556 is good for 1 to 1.5 from a rest.
The DPMS is just plain fun to shoot. I run the 11 inch upper suppressed and the AR 57 upper is the 6 inch with the GemTech can on it.