Honestly, although they don't get much coverage now, back in the day people like Pyrrhos or Antiochos III or Seleukos Nikator... these people had a huge impact on the known world. Pyrrhos was a destructive force like no other; Antiochos and Seleukos, despite losing in the end, were at least as influential as someone like Constantine having reigned over their respective territories 20 or 30 years.

Someone like Leonidas? Pft... fuck him. Ruling over Asia for several decades: now there is something worth remembering a person over.