thenammagazine
Super Freak
The Gate is my all time #1 horror movie it is always overlooked or under rated in my opinion but some other favs have to be:
Tremors
Critters
Fright Night
The Hitcher
Dr. Giggles
These movies are newer but i really enjoyed them.
Jeeper's Creepers(best original monster that i've seen in a long time)
The Hills have eyes(Remake) i was really suprised how much i enjoyed this remake.
Drag me to Hell- Raimi was for sure back in his element on this.
I don't think a single movie on your list went underrated. They all got quite a substantial amount of press before, during and after release.