I would say John.

I think part of the basic premise of this message is that the Apostles and general group of "Disciples" are the same. All of the Apostles were Disciples, but not all Disciples were "Apostles". A disciple of Jesus Christ was anyone during his lifetime that followed Jesus and praticed his teaching. Some would even say that every Christian nowadays can be considered a Disciple of Jesus. The Twelve Apostles were the specific group that Jesus selected to lead evangelistic activity on Earth.

They were the closests of Jesus' disciples in that they got one-on-one interaction with Jesus as a man that most did not. A majority of the Disciples were included in the large crowds of people who followed Jesus. Not everyone in those crowds were Disciples as some were there to trip him up, some were there only for healing and others there for personal gain or to treat Jesus like a celebrity. Treating the two groups as equal is a very common misconception about the Bible. This misconception probably comes from that the Bible refers to them as "The Tweleve". Many would add "The Tweleve Disciples" then it became "The Disciples" to refer to the Apostles specifically. The term "Apostle" is also used in a more general sense to refer to Christians, but this is not the case in the Gospels. I wanted to make sure this was clarified, afterall the goal of this wiki is to help increase biblical literacy and dissolve common misconceptions. If your intent was for the Apostles, I would reccomend editing the title of the thread and noting you edited it with a link to my post. 

I would say my "favorite" Apostle would have to be Paul or Simon Peter. Most of the Apostles don't have a lot of information directly from the Bible and these are the two most common. Paul's impact is probably more noticeable than the others and it is disputed if he was supposed to one of the tweleve Apostles. 

Probably John. He was quick to believe that Jesus was the Christ, and was the "beloved" disciple. Also, he wrote my favorite gospel and book of the Bible. :)

Of the Twelve, my choice of favorite would be Andrew, the brother of Simon Peter. He was the "odd man out" of the inner circle^[1]. He is known best for bringing is brother and others to meet Jesus^[2]. 

1. ↑ Mark 13:3 (Link)
2. ↑ John 1:40-41; 12:22 (Link)