I prefer the AvPR design.
Personally, I feel it was truer to the concept of the Alien creature. Where AvP depicted them as slender - if horrific - avatars of death, AvPR got it right. Their sheer bulk and infantile physical attributes were perfect.
Let's be honest; Giger and Scott were nutjobs to make the Alien as it was. Psychosexuality? Disgusting. Strength and resilience? No-one wants to watch something where the villain might actually win. Intelligence? Not necessary for a drone under the express psychic command of a Queen.
On that topic, the Queen really should've been in Alien. Scott was a complete retard for leaving it out. After all, how cool is the Queen, aight?