Pork tenderloin (里肌肉 - lǐ jī ròu) is my go-to pork cut for almost everything. Stir fried dishes, as steaks, sino-schnitzels, Greek style kebabs, my favourite coriander pork dish and more.
The only other cut I regularly use is pork belly, 五花肉 (wǔ huā ròu) 'fiver flower pork' , but that's a different kettle of pig.