...ICONIC design, did you say? Then...
I would add:
Lange 1 and its variations
Lange Datograph
Breguet 5907 or such simple ones
Grand Seiko SBGW series
Richard Mille (in general)
........
I very much agree with AP RO, PP Calatrava, Rolex GMT/Diver, Cartier Santos/Tank, IWC Mark XV, Omega Speedy, JLC Reverso, and Panerai (in general)....
Nice thread, Imran.
Ken