Here is a perspective from Siem Reap, with 4 Western style Grocery stores.
I wont buy the Olive Oil, especially if its bottled in China. In the States, and in Thailand, I use Filippi Berrio for sautéing ingredients in Italian/Greek/Spanish/Turkish foods, or for Greek Salads. Its used sparsely and more for flavour
For pan fry or stir fry in the states: Peanut Oil. Stupidly expensive here so I use Sunflower Oil. I dont buy oils from China. I dont like the chemical nature of Rice Bran oil.
Everyday use: butter (New Zealand) and Ghee. Real Ghee. Like a Cheddar Cheese Omelet with Tomatoes cooked in ghee. Breakfast time.