For me the definition of a dress watch is easy: keep it simple and modest. So definitely no SS bracelets or chunky chronos. Seconds, date and perhaps a GMT or PR should be the only complications.
I would set my mind on Lange, VC (Patrimony/Malte series), GO (Pano series), JLC (Master Control series), PP (Calatrava series) or the more afordable Longines (Master series) and B&M (Classima Executives series).
My personal choice would be the JLC Master Hometime, GO Panomatic Reserve or the PP Calatrava.