I voted for Jude. I just won't deny her Constance - the role that won her an Emmy, Screen Actors Guild Award, and Golden Globe. Jude was definitely the best written and the best acted.
Like really, the best acting from Jessica while playing any of these characters. Sister Jude is a very close second and Constance was amazing too, Jessica really acts well as anything.
Jude was the best like she was more relateable than Constance. Fiona was good too but she wasn't as memorable as her last probably because a lot of actors stepped their game up in season 3.
It's a toughie between Jude and Fiona, but I'll say Jude. Fiona was likeable in the beginning but she ended up being TOO much of a bitch for me, whereas Jude came around and I ended up really liking her.