Janeway and Seven were great. B'elana I loved in the first season but they never really took her anywhere interesting after Dreadnought. And I did like Kes.
Unfortunately in Star Trek there isn't much competition insofar as female casts go. TOS? Psh. TNG? They could barely get actresses to stay on the show. Enterprise? T'Pol is good, Sato had her moments in the later seasons but was used terribly at the start and barely in general. DS9's the only real competition. I might go with DS9 just cause I really like Kira and I think they just had a better grasp on how to combine femininity with toughness.