Sonic has many freinds but his best freind is "Tails the fox" He is a freindly person that gets on very well with everyone.
Knuckles, and Tails
sonic has a lot of friends. But his two closest friends are tails and knuckles.
As he is a fictional character, Sonic could only be an imaginary friend.
So many i have lost count. depends if you count shadow and knuckles as sonic's friends