Primary Arms M3 clone for me. It has taken tons of abuse utop my DR200. Holds zero fine, bright dot, solid construction, battery life is great. Company also has great customer service.
Vortex Strikefire is another good option. Dot seemed a bit dim to me, but the guy I sold it to loves it.
And for those preaching the high end stuff...
We all don't need battlefield stuff on guns that see moderate use. We don't all have pockets bulging with money. So if you can't offer something useful to answer the question, simply don't reply
remember the old Russian proverb
Perfection is the enemy of good enough
NRA Life Member, SAF contributor.