Look at weapon damage ranges, not just the max damage number. That being said, scythes are very good, and it's not easy to find a good 2h sword, for example. As the game progresses though, most weapons end up being viable, between good bonus stats, high max damage, high crit damage potential, high crit damage multiplier, etc. At level 17-18 Madora is using a pretty beastly orange Tenebrium 2h, nothing else I've found is even close in terms of damage.
