1. Multitool
2. Flashlight
3. Fire Starter

For those are generally a skeletool, Surefire E1B, and some kind of lighter.

What the ideal type of each is could be (probably will be) debated to no end.

Fact of the matter if these aren't generally carried for "survival" in the sense we all think of, they're carried for actual survival on a day to day basis making my life easier. Today I used the multitool and lighter, most days I use the flashlight. Just nice things to have with me. That said, if I somehow ended up outside some night, I could probably get a fire going to keep warm by while I was thinking about whatever stupid action left me on an unplanned night out.