That's a toughie. However, after much back and forth in my own mind, I've decided my four would be:
Paco Rabanne PH
Green Irish Tweed
I picked these because they are all among my all time favorite scents, and they represent the best variety for four frags, in terms of genre, feel and seasons.
P.S. Can we make it FIVE frags, so I can include Kouros?