My first thought on the subject is that it is entirely up to the author - I wouldn't say that one is better than the other, and people have their own preferences. I usually prefer to read books written in third person because I think it allows for more flexibility in the narrative as it is not tied solely to one character's knowledge or view of events. However, I know many books that work really well in first person - sometimes having everything from one person's perspective and really exploring how your character thinks and feels is a huge draw.
Kazuo Ishiguro's style is one that comes to mind when I think of masterful use of first person. In The Remains of the Day, for example, his character interprets and reinterprets events in his past throughout the story, casting a different light on them every time in such subtle shades that you slowly realize his narrative is not necessarily reliable or accurate. Through his eyes, the reader sees that he is forcing himself to believe a certain version of events, blotting out the deeper truths behind it. Or at least, that is my interpretation. To Kill a Mockingbird is another great example of a story whose particulars we see through a child's eyes, completely changing how we interpret events.
If you want to focus more on the bigger picture than one character, though, third person is usually the better choice and can be a powerful story-telling tool. I think it works particularly well in any story with a complex plot, several storylines, or some form of mystery. Just from the two examples I gave, though, it is obvious that first person does not have to equal one-dimensional or simplistic.
So really, I don't have an answer. There are pros and cons to both. In the end, the best thing to do is choose the means of telling the story which makes it easiest for you to communicate everything you want to communicate.