In IWD, after BG, the big variety of skeletons was interesting, new, and also funny a bit. I mean, they use a lot of weapons, like halberds, swords, warhammers etc. and in the same place, so there are no 'pre-made' bow+halberd or dart+hammer units of skeletons.
I love BG, no offense, although IWD is a bit more 'realistic' in this matter: undead use various weapons. The skeleton parties of BG1 were probably raised and armed by necromancers.
Perhaps it's just a detail and shouldn't be discussed, but what do you think?

IWD1 also has a wider 'collection' of undead, like ghosts, wraths and those insane zombies (can't remember their name) who reflect cruelty, human tragedy and undead hunger... unlike the cripple zombies in BG1...

(By the way, BG1 is still perfect. It does not need more undead or such. The lines above were just for comparing purpose.)

I prefer the wider range of undead in IWD, it adds more depth imo, and looks prettier too.
And it's better that they are armed a bit differently too, makes it feel like they were raised with the weapons they died using, rather than being raised and equipped by the necromancer with his buy-one-get-ten-free bargain on darts.

I was always thought it was bit weird to have Undead with bows and crossbows, i mean darts okay, "Here, Skelly throw this at the next party of Adventurers to come through that door, right?" as opposed to "Hey, Skelly can you master that crossbow reloading?" nevermind take arrows out of quivers etc

To me your standard skeleton is a foot soldier, the FR version of cannon fodder. They should have the basic melee weapons as all you have to do is swing these but the more complicated weapon just seem illogical. These should be reserved for your "smart" undead, those Undead Lietenants you get in IWD for example who can talk. The should use bows or at least throw potions at you.

Apart from those gripes the Undead are probably the most diverse group of enemies in any of the IE games and lend the most depth to encounters as igi pointed out above!

The undead are just dead cool....pun intended...sadly.

Yep, the wider range of undead in IWD was a welcome change (not that I would want undead walking on my yard to get a change, mind you) and the more hack'n slash game play was also refreshing.

I really liked the rango of weapons they would employ. The vale of shadows was one of my favourite bits of IWD. They were varied, and just felt more like fighting a diverse army, than fighting through the same monsters over and over.