Well, had to go with (SPOILERS below)
THE INNOCENTS - that scene at the reflecting pool, boy! TURN OF THE SCREW has never been done better.
PHANTASM - probably the greatest boy's coming of age horror film that's ever been made - the terrible realization that your childhood is over and all the future means is people leaving - because they die, sex - which leads to death, getting old - which leads to death and death - which leads to work as you're crushed into a ceaselessly toiling dwarf! Just an amazing movie to see, especially if you're 12/13!. Not to everyone's taste....
VIDEODROME - simply wonderful - Cronenberg saw everything coming years before anyone else, and then made a truly disturbing movie about it. "Turns out, it's from Pittsburgh!" "The world is getting soft, patrone" Just went to see this again last year on the big screen. "Someday, we will all have Television names" ...and we do!. A horror movie for adults. Part of my trilogy of Cronenberg's greatest horror movies (although I like 'em all)
TEXAS CHAINSAW MASSACRE - a Grimm's fairy tale set in modern times - so god-damn grimy and unrelenting! "I'll do anything!" followed by juvenile giggles, because "anything" doesn't mean much to them... "She escaped through a window in hell".
THE DESCENT - maybe jumping the gun on this, in retrospect there might be a bit too much screaming and running around in the dark, but I haven't been so entertained by a horror movie in years - Lovecraft's de-evolutionary fears meet survival horror. Best seen packed into a giant theater with lots of people where the house lights are low, so when the screen goes dark, it is DARK!)
As for the others:
NEAR DARK is great (the bar scene especially), but I still think the end is a bit of a cop out.
FRIDAY THE 13TH is okay. Probably the only one of the series that's actually closest to frightening, in a pure physical threat way but, again, the ending is a cheat (you can't have the mystery killer be a character you never introduced, fer gosh sakes!).
HELLRAISER is a funny film - works great, wonderful re-invention of the concept of demonic deals and a very dark treatment of love, lust and death. But I found myself watching a revival showing back in the late 90's thinking, "why isn't this movie better?" It's not bad - so much works well, but it does have a patchwork feel to it. Still, the Cenobites are stunningly original and there's lots of nice ideas floating around - watch it as a double feature with JACOB'S LADDER and tease out the interesting different treatments of gnostic duality!
THE ORPHANAGE - liked it, didn't love it. Ending, again, a bit too "Lifetimey" (my friend's term, derived from the Lifetime cable channel) and the husband has a very unrewarding role to play.
JURASSIC PARK - lots of fun, not horror to me.