I am not exaggerating. The weapon options in IWD make Cespinar's work look stupid, and these things don't ask for your gold most of the time.
Let's start with a few obvious breakages.
There are 5 melee weapons that confer an extra APR!.
They are Morning Star of Action +4, the Longsword of Action +4, the Bastard Sword of Action +4, Fast Flail +2 and the Valiant Scimitar +2.
The Bastard Sword has suddenly gone from being garbage due to being in a loot table with everything else being +2 or +3 and a boss requiring +2 just around the corner. Now it's probably the best in there. Sure the [Short] Sword of Days having 25% slow sounds really sexy being +3 and all, but I'd rather have a 100% chance to boost the APR of my weapon main hand than 25% slow on it.
And there's plenty at that point you'd enjoy giving an extra attack to.
Not only that! In the treasure room before that, you can find the Fast Flail +2 for yet another APR. Realize that this is around the point XPwise that Charname has just started to explore Athkatla and you can already outfit yourself in enviable ways.
The Morningstar is the best weapon in the game, and that's because it can inflict stun. In fact, there are lots of weapons that can. Stun in vanilla IWD is so good. Less things have Free action than you'd think. Bosses are easy enough to kill with some stun.
If you think you'll have more than enough APR as is on your bludgeoneer, you could try a Shocking Flail +4, which grants +1 Armor, 50% chance for +2D3 electrical damage, and a 20% chance target is Stunned.
By compare the MSoA only has 15% stun and no other effects.
The Longsword is good too, a bit more defensive with +1 AC and 15% slash res.
If you want defensive offhanders though... you've plenty of options.
The best is probably the Bastard Sword +3 Defender, which provides 10% damage resistance, 2AC, and +2 saving throws. Yea, it's the best offhander for a Barbarian or Dwarven Defender.
War Hammer +4 Defender isn't shabby with 15% resist to crush, slash and blunt, with magic in place of missile and the same 2 AC. Sadly, the only saving throw provided is vs Spells, admittedly the most important, but vs. death could be very good as well, and the Sword doesn't share as valuable a loot table as the War hammer.
Then again use both and ask enemies why they even thought they could hurt you at all!
But that's the obvious stuff, lets talk priests and mages... you heard me. There are mage weapons and sanctified blunt weapons.
The Morningstar of the gods is the best one.
It's a +3 weapon with:
Armor Class Bonus: 1
Wisdom: +1 bonus
Memorize 2 additional 1st level Priest spells
Memorize 1 additional 2nd level Priest spell
Other weapons are sanctified versions which only add low level spell levels. You could make this work if you love low level spell spamming... you shouldn't.
For mages, however, there's decent options with mage daggers. The Mage Daggers are a series of +1-4 weapons with decent bonuses and extra mage spells. If dual wielded, you can get a lot of extra magic missiles, especially if you follow with Kontik's wizardry ring.
Ranged Weapons are good too, but in IWD, you can only reach mastery with missile weapons. This made the throwing Ax +2 incredible because of its ability to be grandmastered. Archers can still rule though as long as you stay away from shortbows. Seriously, Crossbows are better for your thief/mage.
There's a +2 Crossbow of Speed, and a +3 Repeating Light Crossbow with a base 3 APR. There's also a heavy version in the same loot table.
In that same loot table is the Hammer Longbow +4 with 4 APR. FOUR! As in, you put that on someone who ISN'T a master archer. Put that on your bard.
Being fair, it is the only +4 Longbow. The +3 Repeater is a longbow version of Tuigan, which should be good on a grandmaster if grandmastery is possible.
A shame about the lacked variety of ammo.
When I've more time I'll get into more stuff, such as weapons you should avoid pointing up.