What is important to me in a good paper or what are the traits of a good paper are very similar questions. For me there are two main traits that really stick out to me when I am a member of the audience: grammar and emotions. I know that the first of these two traits may seem obvious to the reader but it honestly makes a huge difference in the paper. As for the second characteristic, I think that emotions are not as easily as to convey as some may think.
One trait that I find makes a good paper is having good grammar. I hate when I read papers that have too many grammatical errors…especially when they are easy to fix. For example, I hate when I see sentences end in a preposition. If the writer were to just read it aloud, then he or she would realize that it does not sound right. The same also applies to when a question is asked such as, “Where are you at?” Now I do understand that there is character in writing and sometimes using poor grammar is acceptable, but that is all situational. If you are writing a piece, please use proper grammar!
Another trait that I think is important is that papers need to convey emotion. Whenever I am emotionally invested, interested or curious in a paper it makes it much easier to read. How many times have you read something that catches your interest and keeps you interested during the entire story, that it is hard to stop reading? Also, because I am emotionally attached to the story, then I automatically think that it is a great paper. The same should be said for whenever papers are being read aloud. If the narrator puts emotion into every single word that comes out of his or her mouth, then I always enjoy the paper.
abilitski 
I completely agree that grammar and emotion are the things that I even take notice in. I personally hate reading comments from people who right in “slang” term. I don’t understand the concept of it. Is it because people are being lazy when they type? Or do they simply need to re-up on a grammar lesson.