ONE ????? How about just 100?
My white leaf Philo. sport comes to mind.
I have about 15 pots of Sansv. grown from seed I collected after trying to cross breed them. Still unidentified.
I have one plant that is older than I am. I am 71.
I have way too many Sansv. Cylindrica that are about 45 years old.
I have probably 25 - 35 species of Sansv. that I never see for sale anywhere.
My Ficus Religiosa that is about 15 years old that I grew from seed. Seed collected form a descendent of the one that Gautama Buddha sat under.
I am sure I can think of more later.