Which weapon type is the best overall weapon to use for melee? I mean rapier, maul, longsword etc. not ore types.

Rapier

probably spear... from what I know, it's the same speed as rapier and more powerful, and you usually bind your best weapon instead of armor, so it's not a big deal to be w/o a shield (spears are 2-handed). if you can poison spears too, then that's another added bonus. plus you have a bigger variety of attack styles.

Currently I'm using a warhammer, might go with a different weapon later on tough. I find myself having no shield most of the time, so starting of with a 2-handed weapon gives you an advantage for most of the dungeon. Perhaps a spear > Maul, don't know much about 2-handed swords. Would be great if we had all stats listed.