Much like flavored coffee, there are things, like syrup and chicory, you can add to coffee to flavor it. Personally, I stay away from the syrups because they are made of mostly sugar, but I know a lot of people who do use them and the syrups taste wonderful especially when you infuse it in a French press.
Have you ever been to the UK? I have and that was the first place I had ever heard of, much less tasted, coffee flavored with chicory. It was used in US during the Civil War to stretch coffee. However, New Orleans, some Vietnamese and Louisiana blends use it. Chicory adds a mellow, bitter taste. You can buy chicory on its own and add about 10 % to your coffee mix, or to your taste. I think it tastes ghastly and if theres one thing I need to repeat in this site, In my experience, if you go to the UK take your own coffee with a French press.
You can also add your own flavorings. I have added vanilla, ground-up nuts, cardamom, flavored popcorn seasonings, ginger, licorice root, shredded coconut & of course, cat crap.
You can buy coffee flavorings online by clicking on the links above. Generally, a small bottle will cost $5-$20. Chicory is very inexpensive.