Janeway is my favorite captain for sure. The others are all remarkable, because of course they are, but whenever I watch Voyager, I am reminded of how much more I like her over the others.
She had (and used) this great guile to serve her and her crew's needs. She didn't readily break her principles, but would intelligently question them when they didn't appear to align with the greater good or her responsibilities.
She was both flexible and reliable. I feel that some viewers saw that as unpredictability, but I don't think so. She actively did more to help her crew in every way than any other captain we've seen.