A Huskee Cup. Low maintenance, made from coffee husk, great seal with the lid, and I love that it can hold hot coffee but not burn your hands due to the fins running along the body. Many local coffee shops also give me a discount on takeaway coffee if I bring my own takeaway cup, and some offer a Huskee Cup swap program where you can leave your dirty cup with them if you've been carrying it around after drinking your last coffee and get a clean one for your next order (personally I prefer to just keep my own though).

https://huskee.co/huskeecup/