First Thing First a apology for Bad english My Suggestion is the Route From the S1 and S2 From the Verkehrsverbund Oberelbe. 1st ist the S1 from Schöna via Bad Schandau-Pirna-Dresden Mainstadion -Dresden Neustadt-Dresden Trachau-Radebeul-Coswig to Meissen Triebischtal with 33 Train Stadion and with a Travel time of 95 min and Route length of 77 km. The 2nd Part of this Route is the S2 from Pirna via Dresden Mainstadion-Dresden Neustadt-Dresden Klotsche to Dresden Airport(Underground Stadion) 17 Stadions and Route length of 32,1 Km. Trains that are Used on this Route are the Well known DB BR 143/146 and The Dostos. Also in the Past the DB BR 182 and as the Airport Part of the Route wasn't electrified the DB BR 642 Desiro was used. Fright Trains are also seen in this Route with the Classic DB BR180 and The modern DB BR 189.Sightseens on this route are definitely the journey along the Elbe through Sächsische Schweiz, Festung Königstein, Dresden World Trade Center, two large train stations with the Dresden Hauptbahnhof and Dresden Neustadt, and The largest bus depot of the City between Dresden Strehlen and Dresden Reick and more
Between Dresden Hauptbahnhof and Coswig we could also use the Talent 2 From the Schnellfahrtstrecke as RE50. The RE 50 runs between Dresden and Leipzig via Radebeul Coswig and Riesa. There are even Special Runs of the RE 50 between Leipzig and Bad Schandau on the Weekend.