I recently got a pit boss vertical pellet smoker. Done some ribs, butt, chicken quarters, and a pork loin so far been very impressed. My question is can I use any brand pellets, or only pit boss? Just curious

Any brand is what I use

any brand ok. I use the apple wood pellets. milder smoke flavor

Any brand, just keep them dry. Moisture and humidity will cause them to swell and clog the augers up no matter the brand of grill or pellet.

Any brand, just make sure they are food grade for smoking. Heater pellets won't work.

I think most any brand will work. I have the same smoker as you and I’ve used several. Note that apparently when you see flavor wood pellets like apple, mesquite, hickory, etc, in the big box stores, they are normally 75% oak, 25% flavor wood. At least from what I’ve read. If you look into the whole world of pellets, there are some out there that claim 100% flavor wood and of course they cost more. I don’t know how much all that matters in the final product, but just make sure you are getting what you expect and are paying for.