In order of importance and when not tweaking for a specific environment..

1 Knife
2 Fire Starter
3 Communication Device (Radio or Cell Phone etc)
4 Flashlight
5 Whistle
6 Mirror
7 Water Purification
8 Water Storage
9 Compass
10 Cordage

That's whats most important above all else IMO. After that comes FA supplies, particularly wound managment and meds for dealing with fever, allegies and stomach problems that could cause dehydration.

After that I'd say duct tape is next on the list. Everything else (pocket saws, other tools, food rations, etc) is much less necessary or more easily improvised (for me anyway YMMV) IMO or simply more easily done without in a short term (72hr) survival situation.

Keep in mind this is my list for my knowledge level, mindset and skillset. YMMV greatly.

One more note. I find the first 3 items to be trememdously more important than the rest (but you asked for ten so I gave you ten ). A reliable knife, fire starter and communication device (one that will actually work inthe area you're in of course) will take you a looong way with the right skills and mindset