I'll start off:
- It has well written and useful articles.
- It is trusted and reliable.
- It has a sense of Professionalism (Good graphic design, etc)
- The person writing the article knows his stuff.
- The website is very informative.
- Easy usability and navigation.
You can be as general as possible or as detailed, doesn't matter. As long as I could read from a good list of different peoples opinion, it can help me on forming a website, as I'm sure it will help others.