It is possible that the singular/plural choice is not a purely syntactical matter, but partially depends on whether the speaker's focus. I have two assignments, one of them is done. Which one is grammatically correct or better?
One Kind Word Can Change Someone's Day Print, Inspirational Playroom
Which one is the best is obviously a question format, so it makes sense that which one the best is should be the correct form. The first example is incorrect. Which one you use is mostly a matter of preference, although a hundred.
The second and third examples are both correct.
I have two assignments, one of which is done.
