While nowhere near the greatness of classics such as Halloween or A Nightmare on Elm Street, Friday the 13th is a wholly enjoyable film with very little going wrong for it.
Some of the best portions of this film are due to both Tom Savini (special effects) and Harry Manfredini (who composed the music). The gore isn't necessarily that graphic, but there are some fantastic death scenes, such as the arrow slowly being pushed through the next, or the ax to the face (a personal favorite). The music within the film assisted in creating a decent atmosphere for the film, and at times even had sort of a Psycho feel.
Without a doubt, Betsy Palmer gets the highest praise in terms of acting in the film. Her ending scene is legendary, and I feel it's for good reason. Adrienne King did fantastic as the final girl, and it's a shame she never really had that many other big roles in the genre. I also really liked Robbi Morgan (who had a fun personality with her short screen-time), and Jeannine Taylor (she was quite easy on the eyes). Most of the others sort of blended in with each other, but I did sort of like Peter Brouwer also.
I've heard some call this film boring - maybe it's a nostalgic thing, but I don't see it at all. Running around in the rain, wearing slickers, looking for people who have gone missing, only to get killed, with the body being found later by another character - God, it's a fun time. Made better by the fact that one of the characters who could possibly help out is trying to make his way back to camp, but hindered by the rain, a broken-down truck, what-have-you. I thought much of the tension toward the finale was great.
Honestly, when you're talking about the first five Friday the 13th films, there's very little to dislike about them. All five are varying degrees of fun, and all five are easily above average. This first film, with that iconic score and great ending (solid decapitation), is a lot of fun, and I always get a kick out of it, though with the second, third, and fourth films, elements certainly improve. Still a horror classic, despite the unfortunate amount of mediocre sequels.