Third person as that way I can go different POVs if I want to. I guess you can do that with first person pov too but it's harder to pull off. I've only done a few stories in first person pov because I feel you really need to get that character's voice right or else the writing will fall short. I might give first person pov a chance in original works than in fanfiction, though.
Hard to say! I used to be fond of third person (and still am), because I find that it's easier to write a narrative or give an atmosphere when you can describe events that aren't exactly centered on the character (one example that I can think of from my writing today, it felt very unnatural to describe a character's ears twitching in first person, so I decided to write in and maintain a third person perspective for this fan-fiction series).
But I definitely agree that first-person 'clicks' more; I had to do much, much more first-person when I started role-playing, and from there it definitely feels more personal and more easy to relate/be expressive emotionally with the character. Never in my life have done or found the need to do second-person POV though lmao
I used to write in first, but I've recently started writing in third now. It makes it easier when I'm writing main autistic chars, especially if they don't have much eye contact with those around them.
In order of commonality/preference it's 1st, 3rd and then 2nd for me.
Third is my go to, especially since I mostly work on comics right now outside of RP and fic writing here. First person is good when you want to really get into an individual character's head. I generally don't like second, it typically feels weird and awkward to read a story about "me" thinking and doing things I'd never think or do. I think Anna's recent story, Home is the only time I have genuinely enjoyed second person.
Edit: Actually, I just remembered Loomie did a pretty good 2nd person RP post in FF:A. So that's two.
I prefer third person, but then I usually have a lot of characters in my writing. But one of my favorite book series is written in first, so I've been considering trying that out.
I just plain don't like second person. It feels off to me, like someone trying to control my actions. The only time I accept second person is in tabletop games, where I say what I do and the GM tells me the outcome. But not in writing. I tend to mentally edit it to another POV.