Which network topology is easiest to add new nodes to?

I prefer Bus topology in computer networking system because networking is inexpensive, if computer network fails than remaining system does not effect.

Ring is obviously the most difficult because you would have to break the ring to introduce a new node. Bus and Star is quite straight forward but I think Mesh should be the easiest. 

I think The Academic Studies said: BUS Topology is the easiest to add nodes to.

but for my own opinion, i preder the STAR Topology.