The Donauturm (Danube Tower) is not the only place you can get a great view of Vienna. If you want to avoid the tourists, you can grab a drink at the Das Loft Bar & Lounge in the SO / Vienna hotel and still get a beautiful view of the city.
SO / Vienna is near the Danube Canal, where you can find a cafe and restaurant in a boat-like building.
SO / Vienna is a luxury hotel, so you do have to dress to impress. Since we did not plan to go there, we were dressed in hiking gear but for some reason they let us in anyway. We did not get very good service, but according to Yelp no one gets good service here anyway.
The bar is located on the top floor, so you will have to take the elevator all the way up to the 18th floor. The drinks are quite pricey but the ambiance is definitely nice. They have a colorful artistic ceiling, which I forgot to take a picture of because I was too busy looking out the glass walls.
You can see the ferris wheel.
and the Donauturm amongst other landmarks.
Photos taken March 2019.