I still haven't watched the original, but having watched Crystal 1-3 (and hoping the 2 movies adapting the 4th arc come out this year), Ami/Mercury is my favorite of the Inner Scouts and the best Outer Scout for me is probably Hotaru/Saturn.
I like Ami's studious nature and generally can relate to her feeling distant from people (and it's apparently explored more in the 90s anime)
Hotaru is similar in a way, though it's more how she still wants to have friends in spite of still feeling like an outsider because of what her father did to her.