I'm almost repeating what others have said, but you mentioned exactly what I like about Mr. Knightley-his unconditional love for Emma. I remember after reading the line about "faultless in spite of all her faults" for the first time, I first sighed and melted as is appropriate, and then the Greek term for unconditional love, "agape" popped in my head. In the book "Miniatures and Morals" Peter Leithart mentions that Mr. Knightley "speaks the truth in love". This is not some type of infatuation where you are either blind or ignore the other person's faults *coughEdmundcough*. It is where you are aware of them and love the person anyways (or because of them, as Jeffrey pointed out!)
Thanks for your insightful comment! I'm loving this GR!