There are so many interesting things you should know about your facebook friends.
1. Find best friends
Find out your best friends by number of likes they have done on your posts
2. Find who commented most
Easily find the friends who have commented most on your posts, easily read what they have wrote.
3. Friends you have been with (Tagged Friends)
Find out friends with whom you shared most posts on facebook
4. Most liked pictures
Ever curious which picture of you got the most likes, here is an easy tool to find that out.