After trying several different types, my favorite perimeter fence is a five wire with four 12.5 ga red brand barb and the center of the five wires a smooth 12 gage HT on insulators with 6" x 8 ft wood posts every 6th post. Five 6.5 ft tee posts 10 ft apart then the 6th one wood.  Terrain is a big part of choosing post spacing.

I will never again use the lighter gage/higher strength barb wire due to installation problems. It's like trying to work with a huge spring. I have a couple short runs of it but will have no more. True Red Brand 12.5 ga barb is more expensive but a lot easier to install. Some has been in use in this area for 50+ years and still useable when taken out. I just hope they still have a good galvanizing process on the newer Red Brand.

Electrifying the smooth center one keeps cows from pushing on the fence and provides a place to tap off power anywhere for cross fences.  Do not electrify barb wire in a perimeter fence especially.

In the corners, H braces, pinned with a 9 gage diagonal wire.

jmho and experience. Assumes you are fencing for cattle and cow/calf.