So what makes you decide a character is your favourite? What are the special qualities that attract you? Can your own characters share at least some of these traits and what is it about your people that makes them unique as your creation?
I suppose some of the qualities I love to see in a character can be summarised as follows:-
1. Stickability. They don't quit when the going gets tough. They may struggle, they may want to give up, it would be understandable if they did give up, but they don't!
2. Loyalty. This can be to a cause or another quality but great characters are usually driven by something. This can apply to villains too. They may be loyal to a cause (so often it is their own!) but they will have really good reasons for this that you could identify with, maybe even sympathise with a little.
3. Dependability. They don't betray. They will do what they set out to do. They are reliable. I can see the point of an unreliable narrator but have never been that fond of them. I prefer characters who are what they appear to be, even if that isn't nice! (Be fair, you knew where you stood with Hannibal Lecter or Dracula or any of the "great" villains). I suppose it's because there is honesty about the portrayal. Also I worry a little in that as writers we are meant to come up with stories where readers willingly suspend disbelief and could an unreliable narrator break the trust we build up with those who read our work? Hmm...