By the list of responces you could say depending on what the purpose of your crate is as to the size you use.
I have had many dogs and currently only use 48" or XXL crates to night crate dogs in during the winter and for transport i use small 30" crates or crates that only give the dog a small amount of room to move to prevent accidents in transport.
Decid on how you want to use the crate and this will dictate how much extra room you want to give your little companion.
BTW 2 Chi's share one crate and they enjoy their crate