When we start talking about protagonists and antagonists, they immediately tell me it's good guys and bad guys. I don't know who is teaching it this way in high school (grade school?), but I want to find this person and have a nice sit-down with him or her. This idea is so ingrained in their heads that I swear half of them still are running with it at the end of the semester despite my continual protests and awesome handouts.
Just so we are all on the same page:
Protagonist: main character
Antagonist: person or thing that works against the protagonist
So at its most traditional, Harry Potter is a protagonist and Lord Voldemort is an antagonist. Harry being all "I want a normal life" and Voldemort being all "I must kill you Harry" which, obviously, prevents Harry from that normal life fantasy. This is an example of a traditional external conflict.
Also, a pro does not have to be a good person. Actually a pro can be a very, very, very bad person like in American Psycho or Lolita. Here are 18 more books with nasty protagonists if you are interested.
Who do you think they left off the list? Who are your favorite bad guy protagonists?