Here it is!
I lucked out on this question, because I think the series itself answers it beautifully, numerous times.
From the Sailor Stars Kaiteiban musical:
To be a Sailor Senshi is to fight to end fighting, to take the burden of battle upon themselves so others…
Alright guys I was able to narrow down your votes to a top ten, however that top ten wasn’t very decisive so I’ve made a poll for you guys to vote! You can choose multiple episodes (don’t pick them all though, make it somewhat fair) and you can vote every day. I don’t know how long I’ll leave it up (probably once I have a decent number of votes as well as a clear top ten), but I will let you know when I’ve taken it down and have started the gifsets!