spells that you would never want.

[Troacctid]

The Blindness part of the spell works on 6HD or lower. The rest of the spell works on any creature.

No, he's right, the way it's written, anything with higher than 6 HD is immune to the whole effect.

Actually, stinking cloud nauseates them for as long as they're in the cloud plus an additional 1d4+1 rounds after they leave. The cloud lingers for 1 round per caster level and they must make a new save against it each round they remain within the cloud. Positioning it properly creates a barrier in which anything attempting to attack you has a 50/50 chance of being stopped in their tracks. Stinking cloud also carries the functionality of fog cloud, meaning that anything attempting to attack you at a range through the cloud is effectively blind and has a 50% miss chance due to concealment. This is particularly beneficial against the wereboar and its boar pets, who will survive your average fireball on a failed save with just enough HP to realize that you're probably both the most dangerous person in the room and also the squishiest.

Let's be real though. They're going to just walk out of the cloud and attack you in melee.

That's the big problem with stinking cloud, really—it kinda sucks against melee dorks. They pass their save because they have good Fort, and then they walk out of the cloud and attack in melee. It's much more effective against archers or casters, because if they walk out of the cloud towards you, they don't want to be in melee, but if they walk out the far side, their vision is blocked. I almost always go for sleet storm instead of stinking cloud if I'm against melee dorks; hosing their movement tends to nerf them more reliably, and you don't need to worry about undead immunities or whatever. Then you toss a few explosions into the cloud and see what's left afterwards.