Alright, this probably isn't all that rare or unusual (or commendable)... but I like certain
horror rip-offs.
But to make it more niche= ALIEN rip-offs...
of the 80's.
Behold, the trailers for:
GALAXY OF TERROR ('81)FORBIDDEN WORLD AKA MUTANT ('82)INSEMINOID AKA HORROR PLANET ('81)XTRO ('83)CREEPOZOIDS ('87)
Sure, ALIEN can't be beat in what it does. It redefines (IMO creates) a genre. Fortunately for me, as a fan of scifi/horror flicks, a ton of copycats answered the call and looked for ways to ride the coat-tails of Ridley Scott's successful franchise starter. When you get a glut of rip-offs (nearly forming a whole new subgenre of their own), there's a better chance of the cream rising to the top. What these low-budget cash-ins lacked in quality, they made up for in the cheap thrills. Where they lacked in subtley (you want rape and birth, ALIEN, we'll give it to you), they made up for in exploitation. They were gory, sleazy, and highly entertaining in their own right. And (incredibly important), they all featured plenty of practical (ie: latex, goo, models, and matte paintings) effects.

The 1st two on my list were Roger Corman produced, and while GALAXY OF TERROR (Sid Haig, Robert Englund, Ray Walston, and Happy Days' Joanie) ripped off ALIEN... a year later, FORBIDDEN WORLD also ripped off ALIEN
and FW's older brother, the afore-mentioned GALAXY OF TERROR (literally), by re-using footage and James Cameron production designed sets. Neither are officially released to DVD in the US, but both have enough gratuitous everything (
GIANT MAGGOT RAPE), enough WTF moments (
GIANT MAGGOT RAPE), and atmosphere (
GIANT MAGGOT RAPE), to satisfy. Unfortunately, the Corman produced, TERROR WITHIN (late 80's) would not deliver the goods quite like it's early decade predecessors.
If you have any doubts about INSEMINOID or XTRO, merely consult
CHUD's Forgotten Monsters of Filmland List, to be converted.

And lastly... CREEPOZOIDS. Before Full Moon got into full swing, Charles Band (uncredited) exec produced this one. It's got a rodent of unusual size, a pregnant and retarded "cousin of the xenomorph" monstrosity, a killer mutant baby, and a Linnea Quigley shower scene. What more do you need?
If
The Asylum were on its game, like the schlockmeisters of the 80's (hell, even the crappier 90's... LETHAL TARGET, LEGION, Fred Olan Ray's HYBRID, or BREEDERS '98, etc), I'd be a happy man. Asylum's ALIEN VS HUNTER (sucks to be me) is on my Netflix queue, but I'm anticipating disappointment for sure. Maybe the flavor isn't as strange as the thread wants, but in a day and age when rip-offs, sequels, and remakes are so hated, I look back on what ALIEN has spawned and the product of the 80's and smile.
EDIT: Even though it may not fall into this specific category, TERRORVISION (another Charles Band production) deserves a mention. It would not have existed if the scifi-horror genre did not get such a boost a few years earlier by Scott's film (and probably more importantly, the other sci/horror criterion= Carpenter's THE THING).