I absolutely love Stinking Cloud. It has saved me in countless situations that would otherwise have resulted in a TPK. I was able to beat Lord Hungous and the Fiendish Minotaur in Hickory Branch at level 6 only because a timely cast of that spell neutered the bulk bad guys. I do notice, however, that as good as it is, it's actually quite a bit better than it should be due to the enemy AI. As soon as they fail a save in the cloud, rather than, say, using their move actions to leave the cloud and start recovering, the just sit there. As a result, I can either pick them apart with ranged attacks (despite the miss chance- given long enough, it doesn't matter) or area of effect spells (they're still just as clumped as the were at the start). To be fair, I try to take the choice away from them by following the cloud with a web- but still, in a PnP version of the game they would all probably move out of the cloud before that happens. Just mentioning this in case this is something that might be tweakable by mods.
I think it's possibly over-powered anyway. When it gets used against my group, unless I get lucky, it's basically time to re-load.
It can indeed be a nasty spell. Fortunately it is usually only used against me the AoH. If this game allowed PvP battles, you might see a thread to ban its use.
Maybe SA can make a script where combatants try to leave the SC area, like he did for combatants to try to wake each other up after a Sleep spell.
What AI? The AI fails to take account of any battlefield altering condition with persistant effects in my observations. All these area affect spells that everybody is casting are completely invisible to the AI.
I always thought that neutralize poison ought to cure the effects, but I don't think it does -- nothing cures the sickness does it? Anything to limit the effectiveness of an already devastating spell. *shrug*
Here's what the DnD wiki says about .... SRD:Stinking Cloud Stinking Cloud Conjuration (Creation) Level: Sor/Wiz 3 Components: V, S, M Casting time: 1 standard action Range: Medium (100 ft. + 10 ft./level) Effect: Cloud spreads in 20-ft. radius, 20 ft. high Duration: 1 round/level Saving Throw: Fortitude negates; see text Spell Resistance: No Stinking cloud creates a bank of fog like that created by fog cloud, except that the vapors are nauseating. Living creatures in the cloud become nauseated. This condition lasts as long as the creature is in the cloud and for 1d4+1 rounds after it leaves. (Roll separately for each nauseated character.) Any creature that succeeds on its save but remains in the cloud must continue to save each round on your turn. Stinking cloud can be made permanent with a permanency spell. A permanent stinking cloud dispersed by wind reforms in 10 minutes. Material Component: A rotten egg or several skunk cabbage leaves. Here's a link to the source of this post. LINK
It's been my experience that most NPCs save against it and aren't affected by it, whereas even my fighters with huge CON bonuses get whacked by it (Arena of Heroes). I hate this spell, both as a caster and a victim.