Sledgehammer and shotgun.
Sledge is by far the best melee weapon followed closely by clubs, good damage, decent reach, knockdowns are very common, including aoe knockdowns of entire groups of zombies on the sledge.
Shotgun: highest per shot damage in game next to the rocket launcher, Ammo cost is also efficent for buckshot. Good pump shotgun and some str/perks in shotguns, you'll be 1 shoting ferals standing on Warrior difficulty, and if you don't 1 shot them, they are either slowed to a crawl or knocked down. Not tomention with the shotgun tube mod, you can end up with a 12-13 round clip in the pump shotgun.
Worst weapons: Knives, Spear, no knockdown at all on knives, and spear has a unreliable one when you toss your weapon away. Bleed damage on knives is not even stacking properly either. Hunting rifle, it does high dmg, but if that one shot doesn't kill and your fighting something that can run, even with a bandolier+perks it'll probally be in your face right as you can fire that 2nd shot.
Middle Tier for melee: Brawling, has some knockdown thou not as much as sledge or clubs, but at least it has it, problem is crappy damage and low range.
As for guns, pretty much every gun is viable, ak47/m60 are both soild, Pistol is solid, Magnum hits like a truck. SMG is garbage though, its a bullet hose that does about half what a pistol does or maybe a bit more than half, which is really stupid when you can just slap a full auto mod into a pistol and have a higher damage version of the smg. Blunderbus is crap as its always been, Double barrel shotgun is kinda crap too, due to its 2 shot nature, works good early game though, but later on you need the pump shotty.
Archery: meh, haven't touched it much due to lack of feathers and the fact any gun in general will do much more damage and is much easier to get ammo for. You could argue noise but with the lower spawns in a18, zombies coming in from outside is rarely an issue.
Really wish the silencer didn't nerf damage, I don't mind the effctive range hit, but the damage shouldn't go down it should go up like any other mod. Due to that dmg reduction and the fact there are just way less zombies, I don't even bother with a silencer anymore.