I have two.
The AR15, for a number of reasons.
First everyone in the house can use it.
Its ergonomic and easy to use.
Properly built, they are just as reliable as an AK.
Parts, ammo, easily available.
Cost, remarkably similar to a good AK.
I have more reasons but I’ll save that for when I’m not on a tablet.

2nd: The FAL.
While not as light as te AR, and the kids can’t handle it yet, I actually do better with the FAL out past 25y. It fits better.
The power and range thay I gain from the FAL are a boon out here in the mountains. We have elk, deer, bears, mountain lions and wolves right around me. And the extra power also works well on bad guys. And their cars.

Having built and worked on almost everything, these are what I trust.