Multiple kinds of bouillon or similar (a ham flavor isn't super common but very useful)
All the usual ones: granulated garlic & onion, dried parsley, oregano, marjoram, thyme, rosemary. Sage too but I'm just learning to use that one outside of recipes which call for it. Bay leaves.
Blends: Frontier brand poultry seasoning. Italian seasoning. Curry powder, I'm embarrassed to say I don't have a preferred brand yet. Garam masala.
Ground turmeric, ginger, coriander, cumin, mustard.
Paprika, smoked paprika, mild chili powder, chipotle powder, red pepper flakes. Black & white pepper. Chili garlic sauce in the fridge.
Cinnamon, allspice, nutmeg, cloves. Vanilla extract.
Cider vinegar, white & red wine vinegar, balsamic.
Frank's red hot.
Regular Japanese style soy sauce. Chinese & Thai style dark soy sauce. Oyster sauce. Fish sauce. Worcestershire sauce.
Toasted sesame oil.
Since I mentioned oil, a high temp frying oil such as peanut or grapeseed. Refined & virgin coconut oil and butter flavored Crisco for baking.
Edit: how could I forget nutritional yeast.. I live with vegans but I'd have plenty of uses for it even if I didn't.
I think that about covers the waterfront... after HVAC and running water, the biggest thing I am going to miss after civilization collapses is the ability for even lower middle class Western households to have a king's ransom in seasonings if they are so inclined.
Oh, somebody else mentioned live herbs. Fresh basil is nice, fresh cilantro on tap is life-changing. As is having a jalapeño plant.
It's a bit difficult for me at the moment, but I'd really like to refine technique for growing fresh basil & cilantro indoors year round so I'm never without.
Also, rosemary grows wild where I live so I don't actually have dried rosemary on hand.