What are your favorite pantry staples?

Baking - King Arthur all-purpose flour, granulated sugar, brown sugar, Morton kosher salt, Maldon flaked salt (LOVE), aluminum-free baking powder (Rumford), baking soda (good ole Arm & Hammer), honey (I have local varieties of orange blossom and buckwheat), cornstarch (Argo).

Non-Korean rice - arborio, wild, jasmine, brown. I'm not sure what you kept over in Korea, but I can imagine much of it is short to medium grain. If you're not sick of it, yet, that is. ;)

Pasta - I generally will always have a strand and extruded pasta on hand, 2 lbs of each. I like barilla, and generally go for penne rigate and bucatini.

Oils/vinegars - Colavita olive oil (extra virgin and pure), grapeseed oil, aged balsamic (I have a local brand), Columela sherry vinegar (or red wine, but I prefer sherry), Bragg apple cider vinegar, Colavita white wine vinegar.

Nuts/seeds - peanuts (only Planters for me). Everything else I get bulk at the local market, I keep most of em in the freezer: cashews, pistachios, walnuts, whole and sliced almonds. Seeds: white and black sesame, chia, flax, red/white quinoa.

Misc - lentils (green and dal), oats (rolled and steel cut), beans (black, pinto, white/great northern), low sodium chicken stock (I try to have homemade, but backups are good; I like Swanson) Amore tomato paste tube, potatoes (Yukon gold and red are my go-tos), garlic, yellow and red onions, Muir Glen crushed and whole tomatoes, canned tuna (I like Bumblebee packed in oil :-/), JIF peanut butter, Panko bread crumbs,

Definitely agree with Nancy that "essentials" can differ from kitchen to kitchen. That said, there's a few you'll probably need no matter what: oil with a high smoke point for frying/sautéing; a higher-quality oil (olive, sesame, nut) for drizzling and vinaigrettes; at least one good vinegar (I have multiple); one general go-to seasoning mix, either purchased or hand-blended, you can trust to go with pretty much anything; flaky finishing salt (transcends all cuisines); hot sauce/chili paste. This list is far from all-inclusive, but I'm sure you'll get many more suggestions.

While you're at it, consider investing in some storage tools if your budget allows... I'm much happier in my pantry since I started using trays and OXO clear canisters to hold everything.

I think this is a really interesting question but almost impossible to answer with specifics for anyone else....we all have such different tastes and aversions, interests and un-interests.

what I can recommend are categories to include in a pantry:
1) basic ingredients that you use week in, week out. for whatever period your space and budget allow. so you don't have to run out each time for tomato paste or garlic or potatoes.
2) basic main items (protein, grain, vegetables, fruits) that let you put a whole meal on the table if you can't get fresh food (tired, bad weather or roads, blackout).
3) essential ingredients and specialty products for CUISINES YOU ALREADY LOVE & COOK FROM...e.g. for Indian food, gram flour, asafetida, saffron powder, fenugreek, nigella, black mustard seed, cardamon, kaffir lime & kari leaves
4) essential ingredients for a CUISINE YOU PLAN TO LEARN. you need some basics to start just one recipe, so you might as well learn 5 or 10 after investing in the new sauces, spices, vegetables and proteins.
5) a few treats on hand, for impromptu moments of celebration and consolation.

good hunting...