Aliens 2 a better action film than the original and one of my favourites of all time but Alien is still one of the most claustrophobic films I've ever seen at the pictures. I went at the age of 15 (old Odeon on Pilgrim Street you could get in under age Lol) and you could feel the whole audience gasping for fresh air outside after the film.
The one thing that now spoils Aliens for me is Alien 3 as you now know that both Hicks and Newt die in the escape pod anyway. It was such an integral part of Aliens saving the little girl and seeing Hicks survive to then have them both die anyway.
Just an aside. Lol
Also, got to mention the Bond films. Dr No was a fantastic beginning to the 50 year old franchise but then From Russia with Love and after that Goldfinger, were even better.