I love Janeway. I like B'Elanna. Seven was too perfect for me, though I'll agree Jeri Ryan acted the hell out of that role. Kes was a missed opportunity. Seska was evil fun.
I think the best female cast was Deep Space Nine. When Kira was around Dukat, I could really feel her years of anger welling up. Jadzia was one of the most interesting characters since Spock. Tora Ziyal was just a heartbreaking tragedy (believably played by 78 different actresses). Ezri got on my nerves, but she's grown on me. Finally... Louise Fletcher as Winn Adami is my absolute favorite Trek villain.