I think Rosalind is not just the "strongest" woman in the play, but the most realistic character as well. When she falls almost instantly in love with Orlando, she never questions her feelings. She admits them quickly, and with confidence.
In addition to her love for Orlando, Rosalind is not ashamed to admit most of her thoughts and feelings aloud. She commands attention every time she is on stage because she is as knowledgeable and critical of herself as she is of others. You can tell from any of her lines, she is both witty and charming, but not overbearing, nor full of herself. She is thoughtful, and provides wise counsel to other characters Her balance of confidence and femininity have made this character one of Shakespeare's most beloved leading women.