Typically, the protagonist is the main character or "good guy"; the one trying to make things better for everyone around them, or trying to save their friends/the world from imminent danger or destruction...or simply trying to save their own skin. There can be more than one (protagonist) within a story, which is a good thing, as it helps to diversify the various character types within.
By all technicalities, there are as many different protagonist "types" as there are words to define people, but within a group setting there tends to be a "tried and true" dynamic that covers the most basic of roles.
The Straight Edge/Virgin
|Zeddie Little - Apparently, he runs or something|
Imagine "Ridiculously Photogenic Guy" (imagination provided above). Now remove that "what if he's really a serial killer" type thought you just got from that. Congratulations, you've pretty much summed up the average Straight Edge protagonist in a horror film. The "normal", minimally flawed obligatory pretty face. Very commonly they're the main hero or second fiddle to the hero, not just typical "first 30 minutes" slasher fodder. This one tends to last til the end...but that's not always a guarantee. The Virgin is literally the same character, just significantly less likely to have a sex scene.
|Mick and Pnub - Idle Hands|
This one seems to bounce between being your typical burnout stereotype, some form of skater/punk or over-cynical, anti-social Goth. This is one of the characters you're either going to love or find all sorts of irritating because, more often than not, they won't shut the fuck up. Unless you're watching The Faculty, this character is usually dead by around halfway through the movie.
|Trent - Friday the 13th (remake)|
This is the character we all tend to love to hate. Usually, this character is borderline 'roid raging (or PMS'ing) throughout the movie as if being the biggest dick he (or she) can be will guarantee they'll make it through to the end. Unfortunately for them, this tends to not happen that often. Also, this character usually has a 50/50 shot at being more of an obstacle/psuedo-antagonist than being helpful to the main character or pretty much anyone else around them.
|Darren - ThanksKilling|
The nerd is really a pretty typical supporting character. Usually, they tend to be safe and smart until they go all Velma Dinkly and lose their glasses or something. More often than not, the nerd is a useful asset in whatever issue the lead character is having, because when you're being chased by demons or ghosts or what have you, doing research can be a bit difficult. Other than that, the Nerd character is little more than a meat shield with geeky one-liners.
The Hot Chick
Because death doesn't have to be a total sausage fest, we have the hot girl. This particular character (if not the lead) typically doesn't bring much to the movie beyond eye candy. Significantly hotter than the straight edge, this is the character you usually have around for the obligatory sex scene or nude scene. Death usually involves either of the aforementioned scenes.