A splitting axe doesn't get anywhere near the top. Unless used as a synonym for "axes" in general. A splitting axe is too heavy and meant to be swung vertically utilizing gravity for the swing. You would tire out way too fast using it as a weapon, also vertical swings would have a huge risk of self-injury. A 1-handed axe is probably a much better choice, something like a carpenter's axe or hatchet. This could be in the top 5. If you really want to go two-handed axe, a felling axe is a better choice,
And of course, this takes availability into consideration. Something like a Luctern Hammer or Bec de Corbin would make the list of what's actually better. But unless you are next to a medieval blacksmith, I don't know how you would get one. I doubt the ones in a museum can still be reliably used.