[Rawhead Rex]

There is probably no better "real" serial killer movie than Henry, Portrait of a Serial Killer...

Also, Citizen X is a very good movie, superb, I'd say...about Andrei Chikatilo.
The hooker stabbing scene in the woods is awesome.

Confessions of a Serial Killer is really good too...it's based on Henry Lee Lucas and Otis Toole, however, the characters have different names in the movie.
Really creepy moment when the woman lets them in to repair whatever...and minutes later, finds fat-boy Moon (Otis) at her vanity putting on her make-up in a very smiley, creepy manner.

What else?
Deranged was excellent...great 70's movie...saw it as a kid and remember it to this day...especially the bear-trap scene.

Haven't seen Snowtown, but it's in my Netflix queue.

I saw one Dahmer movie where he puts a live dude into an industrial barrel full of acid...don't know the name of the flick, though...

Lots of good movie mentions...
Nice thread.