Rant: The evolving Alien design...

I've been a massive Alien fan since I was 12,the alien design is without a doubt my favourite cinematic creature but over the years I feel like its gradually been chipped away at by people with little respect for the original.With the release of Prometheus (the is it/isnt it alien prequel) I thought I'd look back at some of the Alien designs.
The first Alien design by HR Giger was I think the most successful,tall and slender the creatures head was domed by a milky translucent cover,in the film hints of the ridges underneath can be seen and stills from behind the scenes show an almost human skull with eye sockets.The hands and feet are notable for there human appearance and the creature is clearly a biped.

The mouth / jaw hinge is covered with detail,hands are fused but human

By the second film James Cameron decided to make his own changes,removing the dome and exposing the pattern bones below,the alien looks similar but its hands are now fused into a 3 fingered monster,worst highlighted by the queens comedy monster hand grabbing at a trapped newt through floor grids in the films finale.

Slick black design,Stan Winston added his own touch with the hands

Alien 3 mixed designs,the dome is back and mouth is smaller and more human,here due to the plot the alien is quadruped.Depending which version of the film you watch the creature is either part dog or part bison,the design works but is let down by some bad blue screen/animation.

Alien 3's creature despite being more animal has a more human mouth shape

Alien 4 is where the bastardisation of the design begins for me, largely not because of the head (now with fangs) but because of buckets of goo,mangled hands and feet that look like they belong on a cow.Add to that the "newborn",the hybrid design that looks like Skeltor with a hangover and saggy boobs(and a vagina in his chest) and the alien queen who now looks like a gelatinous blob topped with a hovering UFO head.
Alien vs Predator seemed to follow this alien design closely (apparently the heads were simply repainted) but the film was so dark that most of the details were hidden.

Not only does the Alien 4 have new feet it now also spits acid..and the 'newborn"...

And then there's Alien vs Predator requiem...the work here is shameful,the neck now clearly fits a human head into it comfortably,the mouth has been carved and hollowed out and now looks like a flapping hinged door and the dome is gone.Things only get worse when we see the alien predator hybrid,a lazy mash-up features which couldn't have taken more than 5 minutes to design.I could rant all day about that film..(its about a pizza boy getting bullied by a jock!!!!..an alien film about a pizza boy!!!)

The rubbery Aliens jaw looks disconnected and you can almost see the stuntman's head in the neck and the Predalien..
lazyness.

EDIT:So what about Prometheus? I have mixed feelings about the film and the creatures but may get around to posting some thoughts sometime.Feel free to comment on what you thought and what incarnation of the Alien you think is most effective.