This Special Edition 4 Disc Box Set includes both:

Alien - Director's Cut: Special Edition (DTS - 2 Disc Set)
The first chapter in the terrifying Alien sci-fi saga! Contains the classic 1979 theatrical version and the all-new 2003 director's cut, digitally restored and recut by Ridley Scott!
When the crew of the space-tug Nostromo answers a distress signal from a desolate planet, they discover a deadly life form that breeds within a human host. And so the horror begins - a horror which will end the lives of six crewmembers and alter the life of the seventh forever. Sigourney Weaver stars as Ellen Ripley in one of the most suspenseful and powerful science fiction films of all time.

and

Predator - Special Edition (DTS - 2 Disc)
The ultimate hunter meets the ultimate adversary...in the ultimate Collector's Edition DVD! Arnold Schwarzenegger wages an all-out war against an unseen enemy, a force more powerful and deadly than any on Earth - because the Predator is not of this Earth. Now, you can explore the depths of the Predator jungle with this all-new 2 disc set packed with over five hours of out-of-this-world extras, including an in-depth commentary, director's commentary, never-before-seen footage, revealing featurettes, and more!