The effects may be a bit off by the standards of the 21st century but when this movie came out there were good, not great, but good.  Chris Sarandon is an excellent vampire and Roddy MacDowell is good in almost anything.  Interesting twists on some vampire legends.  I think it has few plot holes and I was never bored with it. Can't say the same for it poor sequel.  My favorite line from the movie is: "you have to have faith; it doesn't work if you don't have faith" because I think that gets to a core truth of the legends and of religion.