Forgive me if I repeat any titles. There are too many already listed to remember!
Requiem for a Dream ~ This is listed elsewhere, but I'll name it, too, as it has one of the bleakest endings of any movie I've ever seen.
Count Yorga, Vampire and its sequel The Return of Count Yorga (as I recall)
Planet of the Apes (1968) and Beneath the Planet of the Apes
What Ever Happened to Baby Jane? (1962)
Butch Cassidy and the Sundance Kid
Madame Bovary ~ various versions
Anna Karenina ~ various versions
Love Is a Many-Splendored Thing
A Walk with Love and Death
Anne of the Thousand Days
John Carpenter's The Thing
Camille ~ various versions
Wuthering Heights (1939)
Romeo and Juliet (1968)
Dirty Mary Crazy Larry
Gone with the Wind
Dark Victory (1939)
The Way We Were
Bonnie and Clyde
Lady Jane (1986)
Duel in the Sun
Untamed Heart
Forever Amber
On the Beach
Charly (1968)
Awakenings
Miracle Mile
Gallipoli