What is your desire out of a muzzle device? Do you want a flat shooter? Do you care about flash? Are you concerned about length? Are you concerned about side blast? Do you want to mount a can to it? Cost?
I've used and or demoed the following.
A2 (Does a decent job reducing flash and muzzle rise slightly)
Battlecomp (Mildly concussive to the shooter and those around. Almost too good of a comp, on my KAC SR-15 it feels like I have negative muzzle rise. Same length as a A2. Is expensive at $150.)
BCM Comp (Great and keeping muzzle flat without any concussion over a A2. No rearward recoil compensation though.)
Surefire MB556K (Flatest and softest brake I've ever shot. No concussion to the shooter. Consequently the loudest to someone next to it and its quite bright at night. Its a long brake. Costly at $150.)
Smith Vortex (Best flash hider on the market. Makes an annoying ting sound from the tines when shot)