Not an easy question to answer, Michael...
The short answer I would say is that you need minimum three watches to cover the basics.
1) Reverso, personally I would either go very simple or very complex. Reverso Rouge or Blue as a simple (any single or duo face Reverso will do). If you want to go complex I would aim for the RG Minute Repeater or Retrograph Chrono.
2) Alarm, even if the TT divers are much more popular, to find the essence of the Memovox, I would go for the modern Master Memovox or Memovox International. They hold the classic DNA.
3) Duometre, the Duometre represent the full skill and knowlage of the brand today (any of the Duo's will do, personally I would go for the chrono). (If olny classic choosen on 1) and 2) there is an option to go for a sports watch here, the Extreme Lab I would be my choice).
Please don't ask me to elaborate this here, this is a very long conversation over drinks!
Funny thing is that depending on when you ask this question, the answer would vary.
Example, if you would have asked this question before 2011, I guess many would not have included a simple Reverso.
If before the birth of the Duometre, no one would include a chrono...
If you would have asked the Q? arround 2000, very few would have included Polaris or DSA.
In the 70's nobody would have included the Reverso!
Food for thoughts.... What is the essence of a brand...? Is it what the brand wants to imply for the moment? Or is it what survived many years after?
Best
Blomman