The horror genre has been notable for its use of sequels and spin-offs ever since Universal first decided Frankenstein could use a Bride. But despite the artistic quality of famous horror sequels like "Bride of Frankenstein," many movie fans ignore sequels on the belief that they can't be as good as the originals. They're often right, but here are six more obscure horror sequels that are actually worth watching.

"The Testament of Dr. Mabuse"

Some horror sequels are so popular and acclaimed that they stand on their own, and many forget that they're sequels. That's the case with "The Testament of Dr. Mabuse," Fritz Lang's sequel to his earlier (and silent) thriller featuring the bad doctor. Lang's trademark use of sound is in full effect, as well as some of the most suspenseful sequences the director ever filmed.

"Son of Frankenstein"

Many cinephiles stop watching "Frankenstein" movies after the second one, since that's the last one from director James Whale. But they're missing out on "Son of Frankenstein," a deceptively great movie that introduced a lot of now-iconic elements to the Frankenstein mythos, including a villain named Igor and a police constable with an artificial arm (fans of "Young Frankenstein" will have a lot of fun spotting the references in Mel Brooks' spoof after they see this).

"Dr. Phibes Rises Again"

Vincent Price's mad Dr. Phibes is one of the great horror villains, so there's no reason not to enjoy his second adventure, the aptly titled "Dr. Phibes Rises Again." In this installment, the hideously scarred (both physically and mentally) Phibes inexplicably rises from his tomb after having replaced his blood with embalming fluid at the end of the first movie - he ends up in Egypt, where all kinds of gruesomely hilarious murders start cropping up again.

"The Exorcist III"

It's all too rare that a movie with the number 3 after the title is good at all, much less as great as "The Exorcist III" turned out to be. The plot, far from being a rehash of the first movie, has myriad surprises of its own. Its most famous sequence, though, is the notorious "hallroom shot" featuring an unfortunate nurse in a hospital who thinks she's having a normal day at work. As you can see in the clip above, she isn't.

"Psycho II"

No sequel to Alfred Hitchcock's "Psycho" ever came close to matching the brilliance of the original. But when the original is one of the five or ten best movies ever made, that leaves a lot of room for the sequels to be entertaining on their own. Any fan of the original "Psycho" will delight at seeing their old pal Norman back in the flesh - but is he back to his old bad habits again? (Spoiler alert: Yes)

"Wes Craven's New Nightmare"

The "Nightmare on Elm Street" series had gotten incredibly stale and goofy by the time the seventh installment rolled around. So, how did the producers inject some new life into the series? By bringing back director/creator Wes Craven, and giving him free reign to explore the same metafictional impulses that would later give mega-hit "Scream" to the world. But a lot of the "it's just a movie, or is it?" ideas that "Scream" made famous can first be found in "New Nightmare."