The Domiplan isn't too bad... many people rant about it, because of its very simple design, but I've been using it exclusively for almost a year (it was the kit lens for the Exa 1b) and found it quite usable. It's the best that can be built with three simple lenses. Now I prefer a Carl Zeiss Jena Pancolar 50mm/1,8 - great handling, great bokeh, pretty good sharpness.
If you actually like that soft look, I recommend a Porst or Revue (they're basically the same) 55mm/1,4. It's got good sharpness at f/8, but wide open it behaves like a true soft-focus lens with an almost-sharp picture and a little halo around it. Its quality is far from modern f/1,4 normal lenses, but it's relatively cheap and very usable, if you don't mind a little softness. I got mine for 40 from the 'bay, but I guess, you could pay less if you keep looking around.