My order is:
1) Neighbors
2) 911
3) friends
I live in the country. We're served by the sheriff's department.
I was vague, I mean if there was a non-medical, potentially dangerous situation occurring at your home.
An example -- late one night I was home alone (and just finished watching a murder mystery, great timing), and I heard a man out front yelling "Hey! Hey! HEY!" I put on the alarm, locked the door and opened the window. I asked him what he wanted. I mean, I'm on a ranch, surrounded by ranches, and he drives all the way onto my place? He then asked if he could park here. Getting weirder. I told him to go ahead, and then I called two of my neighbors (one of whom was wondering who was this person going down the road so late). They both loaded up and came by. I got my dog and followed him (mostly because I thought he was drunk, and if he went the wrong way he'd probably get eaten by pigs.) Turns out he was drunk, and had no idea where he was. My neighbors called his wife for him, and then I called the sheriff (not 911) just to report the incident so there would be a record (I didn't mention he was drunk.) There have been other times I called 911, and either a deputy came by an hour later, or (in the case where I reported that someone was firing a gun in the woods on my place, and I didn't know who it was), they never bothered to show up.
I stick with my neighbors.