Of course everyone knows Sacher, Demel and Central. Their cakes and strudel are on point, but the coffee? Meh.
If you want to try some great coffee, have a look at this list, which was recently put together by a local English language online magazine - https://viennawurstelstand.com/guide/specialty-coffee-in-vienna/?fbclid=IwAR3RGE5wwVAlWpIU_OYSBmVkeS9lHgRgIxi3oahDKwpHPlwFMB8Fc0o_7xg
Many of these spots are in lovely neighborhoods that you probably wouldn’t explore. But they are worth exploring. Balthasar is a personal favorite for their Chai Latte and Swedish buns. Kaffeefabrik is on the recently pedestrianized Otto-Bauer-Gasse, just off of Mariahilferstrasse. Many other cool places on that street, including Café Jelinek and L’Amour du Pain, as well as cute shops.