You might want to add a spoiler alert at the beginning of your comment. I'm sure most of HN has already seen the movie but for those who haven't, knowing that can ruin the suspense.
[Spoiler?]
If the movie is called "Alien", is it really a spoiler to say that you see the alien by the end? I suspect that most of the movie is spent dreading the eventuality that we all expect. ;) Granted it's been a long time since I saw the movie, so I might have forgotten why it's a spoiler.
edit: I suspect that I saw Aliens before Alien, and therefore already had an expectation of what it would look like. Thanks to the sibling/cousin comments for explaining that :)