Don't really like the idea of least annoying...because Midna was annoying at first, but she grows to be the complete opposite and his by far my favorite character. However she does have that initial annoyance so I'm going to go with Ezlo
Princess Zelda, I consider her a helper and I'm ignoring the options you gave because I find them all intolerable. Even though I love Fi and Midna I would not have them on my team ever again, I remember playing Twilight Princess late at night without knowing about my Wii Mote being muted. So I turn it on and I'm playing for like a couple hours.
It's like 4am and I hear this little giggle, my heart stops and I look around to see what made it. I look to the TV and see Midna's little icon flashing..
I don't get why there;s so much hate towards the companions in the game series, yes they can be a little annoying at time but it wouldn't be the same without them, you would feel like you were doing this all alone, and tbh I like each and every one of them the same, just hearing navi's little twinkle hits me right in the childhood and brings that nostalgia feel we all love so much.
Midna is definitely the least annoying out of those three. Fi and Navi bother your whether or not you want them too. The only annoying thing about Midna was her laughing every time you come across a spot where she can do something which was not too often.
Navi isn't that bad guys. Her chatter is not as constant as others. I think Fi would be the worst of the bunch. And just because people hate her so much I will say Navi is the least annoying. As far as being useful I think Midna is the most useful just because she can transport you and change you back and forth from wolf to human
I think Fi is the most annoying she goes on forever about the most obvious things. I was sad at her departure but she was the most annoying. Navi is also annoying but after you play the game so long I just get used to her interrupting me. My favorite was Minda by far I loved her personality and her transformation in the end.
Midna is least annoying to me. She makes conversation with you and helps the story progress instead of only beng good for hints. She was also helpful because she could actually attack and its a pretty awesome attack at that. I felt excited when Midna would say something because it would give the story more depth or leave you with even more questions about her character.