I will not be adding weapons that do not count, weapons that are naturally bad (fists, broken straight, sword hilt, in my mind, everything else is slightly viable), I will write a list of weapons that are poor, and then do a top 10 normal weapons, and then top 5 (maybe 10 if there is that many) twinkle, dragon, and demon weapons.
One more note, I consider a weapon to be not terrible, if it has at least something special going for it. Like the Parrying Dagger is not great for parrying, but it still does that weird 2 parry thing. Its not good, but its not terrible. There are weapons I will not write down that I'm sure many people think are bad for that reason.
Here are weapons that I think are less than less than less than stellar.
Ghost Blade
Astora's Straight Sword
Crystal Straight Sword
Black Knight Sword
Crystal Greatsword
Great Lord Greatsword
All 3 Artorias Greatswords
Mail Opener, er I mean breaker
Hammer of Vamos
Dragon's Tooth
Smough's Hammer
Caestus
titanite Catch Pole
Giant's Halberd
Darkmoon Bow
Sniper Crossbow
Ahh there we go, now like I said, there are many less than stellar weapons, these are weapons I consider to be pretty much useless and why are you using them weapons. I find it ironic that many of them are actually in the special upgrade category. I will do them first.
10: Great Lord Greatsword.
Maybe its because it doesn't flame, or maybe its because its only NG+ stuff, but this weapon is just lacking. Its just a worse weapon to use. It has low damage, difficult to get,
and doesn't light on fire. Nothing is great about this greatsword, but nothing is completely terrible either.
9: Black Knight Sword.
This weapon is also pretty bad, its completely lacking a useful R2 and otherwise has nothing to offer over a good old Claymore.
8:Astora's Straight Sword.
This weapon is clearly designed for early pickup and reward. Although, like another disliked weapon, it scales nicely with 3 stats, the split and low limited AR make it just weak. I placed it higher up because its moveset is good, its hardly impossible to kill someone with it, just a long time to do so.
7: titanite Catch Pole.
I placed this at seven because of the exact same reasons for the Astora's Straight Sword, however, it shares its jump R2 with its R2, and both are really slow and really bad, it's normal R1 and damage I would consider slightly superior, but its complete lack of R2 really is lacking, Halberd class weapons usually have powerful and effective R2s.
6: Crystal Swords.
Both the Crystal Greatsword and Crystal Straight Sword are heavier and cannot be upgraded, as well as unrepairable. They are both useable, but pretty lacking, and have nothing special to offer.
5: Ghost Blade.
This weapon has nothing desirable to it. No great attacks, low range, very low power, hard to get, but it least it works, its just nearly useless in its abilities.
4: Darkmoon Bow.
This weapon is completely useless to a Divine Short Bow, or other similar weapons. There is never a reason to use it whatsoever, however, even though the Black Bow and Longbow are, overall, better weapons, they are also lacking heavily in common duels. Because the Darkmoon Bow works, although completely worse than a Short Bow, it gets higher up.
3: Smough's Hammer.
Most Hammer weapons are a little poor in my opinion, the laughably high STR requirement, extreme weight, and poor moveset makes this weapon very useless. Its does have the extra ability to gain health back, but that looks much more promising on the faster weapons that can do that, this slow weapon is going to get you hurt much more than healed.
2: Giant's Halberd.
This fails for the reasons above, very high weight, very high stats, low scaling. It actually is nearly 100% worse than another Halberd class weapon except for its terrible useless (although different) R2. Never use this weapon almost ever.
1: Vamos Hammer.
This weapon may be easy to use compared to the 2 above, but its AR is so so so bad, its pretty well at 300 Physical, since the fire is going to do no damage almost ever. Its a terrible moveset and stupid heavy. Never use this weapon.
0 (I freaking made room): True Greatsword of Artorias.
MAYBE I'M BIASED Cause I love wolves and I was so happy to get a wolf greatsword, but unlike the other bad weapons, this one takes the cake in my mind. It has high requirements together, weighs a high amount, has a terrible terrible worthless R2, it has high damage, at max stats, that usually still lose to other weapons because its split. Seriously if it did not do split damage, and FAI and INT scaled with that damage, then it would be a unique and good weapon for a few character. I love you Artorias, but I can see why you got destroyed with a weapon like this.
Normal weapons are less than 10, so I'll just do them all.
Mail Opener.
I mean I call it that, there is just no reason in my mind to use it. It is just so much worse than the Rapier for only 1 weight more. The Rapier is amazing, make room, don't use this terrible alternative.
Caestus.
It has terrible range, and attacks fast, but I'd stick with a better Dagger. Is there a real reason to use this? I don't like to be kissing people to hurt them.
Sniper Crossbow.
Sniper, no scope? Seriously, highest range, terrible time to fire, but doesn't have a working scope? If it did, and could actually zoom in more, than it would be maybe slightly useful as some strange sniper rifle wannabe. Stick to the Pharis Bow, or a good bow.
I'm surprised that I named so many unique and so few normal. I guess most normal can be slightly useful, at least Chaos weapons, but the special ones, they either rock or sock.