What do you think is the most effective POV to write in, and why?
This all depends on the sort of effect you want. Every point of view is used for a different purpose. If you want to have a plot-centered fanfic that takes place across a large map, you'll probably want to go for some sort of third-person POV. (Omniscient or limited-omniscient tends to be common in this case.) If you want the readers to sympathize for the main character or to get into the mindset of said character, then first person. If you want the readers to be hit by the events of the story, then second person.
Likewise, every point of view has its problems. First person, for example, tends to be incredibly difficult to pull off because you're restricted to the mindset of a character, which in turn is limited by his or her mental state or setting. For example, take the novel
We by Yevgeny Zamyatin. Fantastic novel, really establishes a dystopian society. Problem there, though, is that we're led to question whether or not the government
really has a hold on the main character's mind because of the fact that he's
not just spouting propaganda (despite the fact that he's loyal to said government, which believes that every mind must be a machine, and can't remember a time when humanity was actually free). For an easier example that doesn't get into pretentious lit crit, imagine attempting to tell a story from a baby's point of view and think of all the ways that you'd be restricted by that mindset. I've read stories that have attempted this kind of narrator but failed because they forgot who their narrator was.
Additionally, we're limited by the character's knowledge, which means that the narrator has all the potential for becoming an unreliable narrator, or someone who may or may not constantly misinform us as to what's actually happening. Think of a mystery novel told from the murderer's point of view. He'd probably not admit right away that he's a murderer (especially if he's speaking to the audience instead of letting the audience psychically enter his mind), which means that the entire story might not be revealed to us as it actually happened. While there
have been writers who can pull this off, it tends to be very difficult for someone who hasn't written almost all their lives, if you know what I mean. (In other words, you need to practice to pull off that sort of effect plausibly.)
On the other hand, first person is also one of the more dramatic points of view. The limitation and the constant questioning of how reliable the narrator actually is, when done well, can get the reader to really think and piece together the story in a way most other points of view (namely, the third person varieties) really can't. Additionally, as I've said before, the first person point of view tends to also force the reader to feel something for the speaker, given that they're the ones leading the reader through the story, which adds to the dynamic effect of the climax and resolution of the work. The unfortunate point to the matter is, though, that if it's
not done well (which isn't entirely difficult to do), it either makes the narration weak or confuses the reader (in a bad way).
Personally, though, I prefer the third person points of view. While they tend to be drab (because the reader can see everything, not just the narrow view of the character's eyes, especially if the specific point of view is omniscient), it's also easier to work with. Every detail you want the reader to see can be passed along to said reader without having the author really think about how to get the narrator to look in the direction of, for example, the gun on the wall without making it come off forced, if that makes sense. That and you can poke into the mindsets of any character you want (one, two, all, none), which can sometimes help explain things to the reader a bit clearer... unless, of course, you choose to go the Hemmingway route and limit the amount of telepathy the narrator uses on the characters.
Preferences aside, it just depends on what the story calls for, I suppose.
