Domāne Wachau stands out as a favorite of mine by far. The older FX are good but lately the Kellerberg component has lacked something. I like the Achleiten from DW most of all, but a new favorite is their Amphora fermented riesling. Try it you will love it. Any of the better wineries in that stretch outside of Krems are worth a visit I think. If in Vienna, swing by Pub Klemo for a sampling of great Austrian wines.