Considering the current state of weapon balance, I think buffing underperformers should be the first step. That’s not to say that some weapons might not need a (tiny) nerf here or there, but right now there aren’t many weapons that absolutely overperform in a way that’s harming the game. Buffing bad weapons first and seeing how the meta ends up would be a better choice currently.
Here’s the weapons of which I think need a little love, based on personal experience with them:
Mace / Hammer & Shield
This one is just outclassed by Sword / Axe & Shield in every situation and against every enemy. And that’s while these other shielded weapons are definitely on the lower end of the power distribution as well (but fine enough for now). The main reasons for that are: 1) Armor damage (Axe attacks and Sword Pushattack - Heavy 1 combo are waaaay superior), but mostly 2) Lacking the beautiful Push - Shield Bash (Heavy 1) combo. Sword and Axe do have that combo and the capability of the first attack being that glorious Shield Bash, and therefore their potential for control is way superior, and that’s one of the main reasons to bring a Shield weapon in the first place. Also, the Hammer / Mace light attacks are pretty much redundant on this weapon since its Heavies do what the Lights do better in every way.
I’d buff this weapon first by changing the pattern of its Heavies so that the first Heavy is the Shield Bash. I’d also buff its Lights in some way. Those changes would make this weapon a lot better, but it does risk making this weapon a little too similar to Axe & Shield. I think other people might come up with more creative buffs though, and maybe a complete rework might also be in order…
One Handed Axe
This weapon is almost good, but it suffers a lot from one thing: Difficulty scaling by increasing enemy health disproportionally affects some weapons over others! (And that’s a main problem for a lot of other weapons as well.) For example: If a weapon / attack does what it does not by killing a single enemy quickly, but by having the capability of controlling and damaging a lot of enemies at the same time, that weapon / attack is still good if the enemies have more HP. You fight in exactly the same way, you have the same pros vs. cons, but fights just take a little longer, basically.
If instead your weapon has the benefit of killing an enemy in one or two strikes, at the cost of having bad control and defense (like the Axe), that could essentially work fine as well. You just need to use its mobility, but also tactically pick which enemy to strike to kill them quickly before they can attack you; Use the Axe’s offense for your defense, so to say. But when enemies now suddenly don’t die in one or two strikes because of damage sponginess, the weapon loses all its benefits, while still suffering from the negatives! The Axe is fine when it kills Fanatics / Ungors in one hit and Gors / Marauders in two, because that’s when its negatives are compensated by its killing power. When that doesn’t happen anymore, however, the Axe suffers a lot.
Barring a rework, I therefore think the Axe simply needs more Damage. If it can easily hit the breakpoints I mentioned earlier without giving up Crit Chance and Attack Speed, the Axe is a perfectly fine and viable weapon. Try it: Play it on Zealot with his damage buff vs. on Bounty Hunter (on Legend) and you’ll see what a world of difference that makes in viability. Potential problem could be that ithe Axe then becomes either good in Legend but bad in Cata, or Good in Cata and maybe overpowered in Legend… But I think even if the Axe can oneshot Gors in Legend it’ll still not be overpowered compared to other weapons.
Suffers from the exact same problem as the Axe: When something you shoot is not deleted instantly, this weapon becomes useless because of its downsides (low ammo, slow reload). When you need two shots anyway, a more spammy weapon like the Repeater Handgun (or not switching to a ranged weapon at all!) is better in every. single. way.
Making this weapon an option is easy: It should, in every situation, on any difficulty, kill anything that’s not a Chaos Warrior or Monster in one hit. Period. You could even increase the reload time a little to balance this out. The damage it does vs. Chaos Warriors currently is pretty fair, though, so in compensation its damage vs. Super Armor specifically could then be reduced a little as well to keep it at its current damage.
One Handed Mace / Hammer
Pretty much outclassed by Sword & Mace or Dual Hammer, and way worse at Killing than it’s benefit of reasonable (but not great) Control capability justifies.
I’d like to see a buff to its Lights & Heavies in Damage and Armor Penetration, but I realize it could quickly become too similar to the Axe. Maybe just a tasty high Headshot Damage bonus instead? I’m sure other people have good suggestions as well.
Two Handed Axe
Mostly needs a buff because it’s overshadowed by the Two Handed Hammer. It just doesn’t kill fast enough to compensate its bad Defense / Mobility and mediocre Control.
A buff to Attack Speed and / or Damage could be enough to bring it up to level. I have a sneaking suspicion that it’d also be easy to buff this weapon into overpowered level, however, so some prudence is in order…
I like the concept of this weapon, and it was perfectly fine in 1.6, but it underperforms right now.
I’d buff its lights a little maybe? Or instead give it some more mobility? In either case, a fully charged headshot should be able to kill anything that’s not a Chaos Warrior or higher in one hit in every situation. That alone would make the Warpick good, but still not overpowered since its charge time is very deleterious when facing mixed hordes.
all One Handed Swords & the Falchion
I never played these weapons very much in 2.0 and upwards, but they always felt very underwhelming.
Not really sure how to balance them properly since I lack enough experience with them, but it seems to me they could use some love.
There has already been said a lot about this one, and it’s on FS’s radar, so I won’t go in to needless detail here. The fact that it needs a buff seems uncontroversial to me, though.
Those are probably not all the weapons that could stand to be changed, but they’re the ones that need it most and the ones I have most experience with to form an opinion about.