I chose Fi. She's just sooo annoying. She gave a lot of info, but almost none was useful. I've never found Navi annoying, when she says "Hey! Listen!", it only lasts like half a second, and then she says really short things. Fi, on the other hand, her beeping takes like 20 seconds to stop and she says a lot of useless stuff and the text is SUPER SLOW. Besides, Fi didn't have any emotion. Sometimes, I forgot she was even there; like in Eldin Volcano when yu lose all your stuff, when I found the sword, Fi says something like "Sorry I left your side", and I was like "You left??".
Fi. She gets annoying with pointing out how many hearts you have and all that. Although it is interesting that she is a computer(my sister found that out). The little electronic guy in the game falls in love with her means she is a computer, and she talks like one. But yeah, she is my least favorite.
Navi had very little character and didn't add much to the story line other than at the beginning. I mean, besides, who hasn't been annoyed to be in a big boss fight and then hear an obnoxious little voice go, "Watch out!"
Fi, is definitely my least favourite, as people say, you can ignore the fairy companions but you can't ignore Fi. I didn't hate Fi though, she looked wonderful, probably the best looking companion Link will ever have and i loved it when she danced too, i wish she would have grown in personality a little bit like Midna did, SS was brilliant for characterisation but it seemed to completely ignore Fi.
If i could have ignored Fi, then she probably would have been one of my favourites but she didn't waste anytime in telling you something you had JUST been told.