I hope to expand this section, but I guess I could do worse than to start with some Nobel Prize winners!
Nobel Prize Winners:
Awarded the Nobel Prize "in recognition of his services in the discovery of the inert gaseous elements in air, and his determination of their place in the periodic system".
Participated in many Esperanto conferences and meetings.
"In recognition of the great merits of his theoretical and experimental investigations on the conduction of electricity by gases".
Vice-President of the International Esperanto Science Association.
"Founder of Die Friedenswarte" (a peace publication).
Author of an Esperanto textbook and contributor to the magazine L'espérantiste.
"In recognition of his work on anaphylaxis".
"For his discoveries relating to synthetic compounds that inhibit the action of certain body substances, and especially their action on the vascular system and the skeletal muscles".
Learned Esperanto as a first language.
"For [his] pioneering analysis of equilibria in the theory of non-cooperative games".
Author of two books in Esperanto on games theory.