How much (or how little) do you want to spend?

I have one of these $19.99 red dot sights:
mounted on a Savage Axis. The dot is 3moa and is perfectly fine for the distances I shoot (up to 200 yards). This is NOT a robust battle sight, but for a rifle that is only carted to/from the range in a padded case and then taken into the deer woods once a year, it is good enough and holds a zero very well.

If I were looking for a battle sight, I would pay the money and go with an eotech, but for something I would actually carry into a gunfight, I prefer to rely on iron sights.