My mother had a habit of watching The Devil's Advocate whenever it was on television, and was perhaps her favorite Al Pacino flick. Put Al in a movie and she would probably watch it: but The Devil's Advocate was one she enjoyed. Personally, I had always tended to skip it; citing that it's not my kind of subject matter. As a kid, I'd usually opt to be elsewhere and over the years have probably seen only bits and pieces in passing.
Seeing it pop up on Netflix: I finally opted to watch it. If I've ever seen the whole film straight through: it's probably been around twenty years. I have to admit it's easier to notice how great the film's execution is than as a kid.
I rather love how Al's character of Milton is so utterly insidious. As he warns Kevin, "He's the one you never see coming". Because that's how things go to hell. How the notion of free will and temptation fit into the story is surprisingly well crafted. The ending is also pretty damned spectacular.