The best choice for lubricating o-rings in a fluid system is usually the fluid used in the system.
Most fluids have "some" lubricity, and you will have zero chance of harming/deteriorating the o-ring with the approved system fluid. If you use coolant on the water-pipe o-ring, it will live forever. Same with using power steering fluid on the 0-rings in that system.
The same cannot be said if you get "creative" and use petroleum based products on an o-ring that is not rated for it. Engine oil has a whole range of additives, and not all of them are "good" for the long term health of a static seal.
That said, I (and most of the techs I know) use a schosche of pure petroleum jelly on fuel injector o-rings.
A little in the right spot goes a long way!
It will help prevent the little o-ring that seals the fuel from rolling in it's groove, which almost always results in fuel seeps/leaks further down the road.