I've been lucky to see several species in my life.
My favorite experiences are:
When about 11 or 12 we discovered a hole in an apple tree on my Aunt's farm. We peered inside and there was a screech owl peering back at us.
Living in the Midwest my whole life I never observed a barn owl. Until a few years ago while driving back from Volcanoes National Park on Rt200 on the big island Hawaii. There in the headlights we observed a barn owl. Of all places, that was the last place I expected that.
Finally, while hunting ducks hunkered down amongst tall grass along a stream near the end of the day, several short eared owls appeared. They would dive and swoop, sometimes getting quite close if I happened to move my head or hands. Really wished I brought my camera.
I've also observed Great Horned, Barred and Burrowing owls.