Janeway was my favourite, followed extrememly closely by Picard, and not just because Janeway is also a woman. Voyager had to go through more exenuating circumstances than Enterprise ever did, especially being 90,000 light years from the Alpha Quadrant, she would have had to learn to bend the rules eventually, and yes, while Mulgrew's character was inconsistently written, a Starfleet Captain (well, really, any captain) should have a stable presence along with the ability to lead, Janeway has that. I think because of the long journey to get back to the Alpha Quadrant, some of Janeway's inconsistencies would have been from her having to try and maintain respect from the crew as a captain, but still be there for them because they have pretty much no where else to go.
Jeri Ryan, while not bad, would not have been captain material i don't think, she's more eye candy than anything else, and she wouldn't have been taken seriously as a captain.
I've never seen all of Deep Space Nine, it just couldn't hold my attention, so I can't make an educated opinion on it. My biggest issue with The Next Generation is that the story remains fairly static, there is very little character development (certainly less than in Voyager), but it gets points because i like Deanna Troi and Patrick Stewart.