Goodyear excellence would be a good tyre for your Audi A4, to begin with. It offers a very comfortable ride quality and is widely used as an Original Equipment on various luxury vehicles.
Another good option would be Yokohana DNA db ES501 tyre. This tyre is popular for its very quiet and comfortable ride quality along with great handling and traction.
Another good option would be Michelin Primacy 3ST. This tyre offers great comfort, even on rough roads, along with superior grip along and enhanced tyre life- A great value for money option.
In case you want something top of the line, then Pirelli Cinturato P7. This tyre triumphs in all spheres including traction, ride quality, quietness and handling. The tread life on this is pretty good as well.