Yeah I'm also going out on a limb and assuming you meant Tatl as well. In that case, yes Tatl is the best of the three. I have absolutely no issues with Navi at all, but Tatl definitely had more personality in my opinion. You start out hating her because she's in league with Skull Kid, but by the end you really start to care for her.
Navi serves her purpose. She gives information and tells you were you are suppose to go. While she really doesn't have much personality or dialogue after the first couple of minutes, she is still a great companion. I personally just like characters that actually have more personality. I never found Navi to be annoying and the only reason that I ever say she is, is because it is sort of a Zelda stereotype to ***** about her annoyance. It's fun to make jokes about her, but in reality she's perfectly fine.
Fi on the other hand is annoying as hell. She gave me information that I already knew (like go forward), sounds like an autotune (well not as much in my second playthrough), feels the need to tell you that your hearts are low by beeping over the already present beep, and has absolutely no character development except for some forced lines at the very end of the game. Yes I know people will always argue that she isn't suppose to have character development and if so then I'll say that even if she is suppose to be a robot with no emotions, I prefer every other companion to her.
I am curious as to why you limited it between only these three though. It seems kind of random to just pick these three. I mean if you were going for all fairies, then why did you leave out Ciela from Phantom Hourglass and include Fi who isn't a fairy, but rather a spirit (which I guess could be the same thing depending on how you look at it.) Maybe these are just your three favorite companions, but if so, then I'm sad. Why no Midna, KoRL/Tetra, Zelda (who is also a spirit/fairy...sort of), or Ezlo? But especially Midna....seriously why you no love Midna?
I've probably written why I love Midna enough times, so I'll just shorten it to say.....Midna had the best character development and I personally enjoyed her the most out of all the companions. Midna is the best and could only have been improved if she gave information on enemies in the way Navi/Tatl did it where it was short and sweet as opposed to how Fi did it which was hard and long (