Best one for the money, hands down. - Burris AR-Tripler Rifle Scope w/ AR Pivot Ring

Very clear glass. I use one of these with an Eotech and one win an Aimpoint PRO. Fits behind them both like a glove. BUIS on the rear will force ya to put your red dot a bit forward. But this only takes up two slots of your rail. Mount is very tight and true and holds firm. I would trust this optic to do it's job even after I have banged one of them around quite a bit.