My favorite Halloween movie is the original Halloween (1978, Jamie Lee Curtis, Donald Pleasance)! I watched it the first time in a big old movie theater... and a real bat was flying around the entire time!!

And although not the best-acted movie, Prince of Darkness (1987, also with Donald Pleasance) is in my collection and is *always* worth a late-night watch!
On the not-so-scary side, Hocus Pocus and Practical Magic are so much fun!!