Gosh, I think back and remember horror movies that weren't the average flicks. Even when special effects were new to the genre, movies like "Critters" did an awesome job in accomplishing to create, little freaky, spikey, goulish creatures that were scary to me as a child, because those things could've been anywhere if aliens did land. Scary but believable only in a child's eye.
The monsters weren't the typical little green men, grey people, flashing light stuff that came with a common alien movie. No, these were dust bunnies straight from hell, who shot out poison spikes and ate people, while rolling up into balls.
The sequels were tardis at best sometimes with a general 80's style of punk, but there's something about small creatures, with glowing eyes and razor sharp teeth that did freak me out way back when. I think the monster FX attributes themselves though happened to be way better then the totally unbelievable computer animation that's ruining today's (modern day's) B-Movies.
The first "ghoulies" movies played on the same FX technology which was close to none. But it was still better than computer animation.
When "Troll Hunter" comes out, I hope it has the same original qualities in the design of the creatures.