"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. This is very good instinct, and you could even argue that the grammar is good, but at best it's unnatural.
The first example is incorrect. The second and third examples are both correct. Which one you use is mostly a matter of preference, although a hundred appears more frequently than one hundred. There is also another form, an hundred, which was common in the past, but has mostly fallen out of use. See Google Ngram Viewer: a hundred, an hundred, one hundred:
Which is correct: "one or more is" or "one or more are"?
Which came first when saying numbers: "one hundred AND one" or "one ...
When using the word " which " is it necessary to still use " one " after asking a question or do " which " and " which one " have the same meaning? Where do you draw the line on the difference between " which " and " which one " when asking a question that involves more than one answer?
Noggin, Paramount Global‘s interactive learning subscription service for preschoolers, is shutting down, sources tell Deadline. The Nick Jr.-affiliated app is slated to sunset this year, with the ...
Noggin, Nickelodeon’s interactive learning platform for preschool-age kids, is shutting down after almost 10 years, Variety has confirmed. Noggin is a casualty of Paramount Global’s companywide ...
Noggin is shuttering. The Nickelodeon subscription-based streaming app will shut down after Paramount Global laid off the entire team behind the platform. Targeting the two-to-seven-year-old demo, ...