Two ways to go. If you want a SHTF/TEOTWAWKI rifle, the Trijicon ACOG with .308 reticle is the way to go.
For hunting/plinking, I would get one of the 1-4 0r 1.5-5 scopes from Leupold, Nikon, etc.
Of course, it you can afford it, a Swarovski, Nightforce, S&B.. .............
I didn't fight to defend your freedom so you could vote to take away mine.
"A man who has nothing for which he is willing to fight, nothing which is more important than his own personal safety, is a miserable creature and has no chance of being free unless made and kept so by the exertions of better men than himself.
John Stuart Mill."