My favorite coffee flavors are cinnamon, cocoa powder, vanilla and whipped cream. They are good in/on coffee. Especially on Cappuccino. Currently the Cappuccino is my favorite type of coffee. I often put multiple of these on/in a cup of Cappuccino (for example cinnamon, cocoa powder, whipped cream). So it is good to mix various flavors. Of course this depends on everyone's own taste.
Have a nice day. All the best. Greetings and much love from Hungary.