I voted other because i use all of the above.
There is no best way to sharpen a knife,It all depends on the knife,the knife steel,what you are using the knife for and on the person.
Heres an example,food knife i use a butchers steel,Machete i use an oil stone,camping knife i use a diamond card and strop.
If im making a knife i will use different stones and work down in grit till the knife is sharp then ill use a diamond card and then strop.
I also use an idea that finnMan gave me but he can explain that better than me.