You could also theme it similar to Midgard, the slain are taken to the afterlife where they fight in an epic war, taking them from their glory is not only unnatural, it is completely dishonorable. This makes it so culturally biased against the idea, that even evil people will be rare to break the taboo, meaning when you do use undead they can be completely custom to avoid players feeling like "great, more skeletons/zombies/ghouls".
(Note: This also has the side effect of not keeping the fallen pc's gear other than consumables, since they will need it in the afterlife, meaning less vulture-ish PC's.)
You really need a group of players who will embrace this concept, or it won't really work.
Also, take all the insta-death Spells and SLA's out of common monster stats, and make them more rare as well.
The idea is that since your death affects your status in the afterlife, death magic with no chance should be just as shameful to use since it cheapens the death.
Of course, truly evil villains will do it, and some special "advanced" monsters will have it, but it should be more of an epic battle of attrition than insta-win spells.