I like the second one for the action, but I lean more towards the first, since it has the original Giger designs, and because the suspense makes you so high-strung.
For those that really, really like the film I would recommend getting the book 'Giger's Alien.' It's pretty much Giger's diary of the production of the film from start to finish.
A lot of people don't notice this, but the 'alien' is simply a physical representation of the unbridled, animalistic sexuality of both females and males. Giger took a simple horror sci-fi film and, with his art, turned it into a commentary on mankind's (irrational) fear of all things sexual, from intercourse to birth.
"Giger reminds us that unless we can accept, admire, use these tentacled, lizardy, octopus ancestors from our past then we die fearful, superstitious urban robots. Giger's paintings like those of Blake and Dali are basically loving and raunchy-erotic. They tenderly, humorously confront us with the ribbed cages, the sleek struts and tendon fibres, the smooth-lube-tubes of our own beloved soft-machines. And the warm, moist, squishy carnality of our lovers." -Timothy Leary
Giger is definitely my favourite artist.