Just my 2 cents on a surface-level reading of the character because it's also been a while since I've watched it.

Aragorn is strong and capable, with a generally masculine image about him. He's handsome, good with a sword, rides horses, and commands respect by his presence.

But he is not prideful or boastful, he doesn't seek glory, and he's respectful to the women in his life.

At least the way the movies present it, his relationship with Arwen is one in which both partners are equal participants. Aragorn is not controlling, and Arwen isn't some damsel who lacks agency without her man there to tell her what to do. And when Eowyn shows affection towards him, he is quick to respectfully decline her advances without leading her on, thereby preserving a positive and supportive relationship between them.

That might be the sort of thing people are referring to, as far as his characterization. There might be more examples, but that's what I remember.