I’ll second this. Most people in the US don’t realize how good black mulberries can be. They travel badly so they are almost never in stores, they only grow in warmer regions, and have a very short shelf life, but they really are one of the best berries that exists. I’m not sure I’ll go as far as growing one in a pot, but if you are somewhere you can grow one outside you really should. Make sure you get the real thing, though. Many things sold as cold hardy black mulberries aren’t Morus nigra. Morus rubra (red mulberry but the berry looks black) can be perfectly tasty, but just isn’t in the same league.
For me in chilly Vermont, I’m going to claim that haskap/honeyberry have lived up their hype. It’s a very small hype, and the vast majority of people in the real world have never heard of them, but I planted a bunch without having tasted them and they’ve met my high expectations. They grow well here, they produce heavily, they are relatively pest-free, and they can be really tasty. There’s some tricks about them (newer varieties are generally better, you need to net them for a couple weeks after they turn blue, they are often better cooked than raw) but they are a really good fruit for colder climates.