"Casablanca" (1942) Starring Humphrey Bogart and Ingrid Bergman, this is the film against which all other top romance movies are compared with, and generally found wanting. Rick and Ilsa are reunited, but she's married and he has to make the hardest decision a man can ever make.
"Love Story" (1970) Ryan O'Neal plays Oliver Barrett IV, a rich kid who falls for Jenny (Ali MacGraw). His dad disowns him when he marries Jenny. She develops leukemia, and he is reunited with his dad shortly after her passing. His dad apologizes, and Oliver tells him what he learned from Jenny. "Love means never having to say you're sorry."
"The Way We Were" (1973) Katie (Barbra Streisand), a young Jewish woman who is heavily into politics, falls in love with Hubbell Gardner (Robert Redford). He finally returns her feelings, and they wed. He cheats, she realizes he will never be the man she idealized, and the marriage ends. When they are reunited sometime later, it's obvious Hubbell still loves Katie, but he could never be the man she needed him to be.
"Ghost" (1990) Sam (Patrick Swayze) and Molly (Demi Moore) are madly in love. His business partner has Sam killed, not only to cover the fact that he's an embezzler, but also because he wants Molly for himself. Sam stays in ghost form and is able to protect Molly and even say a final goodbye.
"Dirty Dancing" (1987) Baby (Jennifer Grey) and her family arrive at their annual summer resort. Baby, the sensible one, promptly loses her heart to Johnny (Patrick Swayze), the dance instructor. It swiftly becomes mutual, but Baby is off-limits and so their love must be kept secret. Johnny finds her sitting with her family and says "Nobody puts Baby in the corner" before putting on the performance of a lifetime for the guests.
"The Princess Bride" (1987) Buttercup (Robin Wright) has an admirer in the farm boy, Westley (Cary Elwes). "As you wish." Whatever she wanted, if it was within his power to grant, he would. That alone would land this movie a spot in this top ten romance movies list. Buttercup is kidnapped by an evil prince intent on forcing her into marriage, but Westley (aka, the Dread Pirate Roberts) saves her from a fate worse than death.
"West Side Story" (1961) Tony (Richard Beymer) and Maria (Natalie Wood) fall in love, and that's a bad thing. Tony is American, and belongs to The Jets. Maria is Puerto Rican, and her brother is with the Sharks. They fight to be together, but in the end Tony is shot by Chino, the man she was supposed to marry.
"Somewhere in Time" (1980) Richard Collier (Christopher Reeve) travels in time to meet his one true love, Elise McKenna (Jane Seymour) after an elderly woman approaches him at the opening night of his first play. "Come back to me" she says, and he undergoes hypnosis to do so. When he sees an object from his time, he returns to his own decade.
"The Bridges of Madison County" (1995) Robert Kincaid (Clint Eastwood) and Francesca Johnson (Meryl Streep) cross paths when her family is at the state fair for the summer. They were only together for four days, but she filled three journals talking about it. Now that's love!
"Romeo & Juliet" (1968) With Leonard Whiting and Olivia Hussy in the title roles, this is the version of "Romeo & Juliet" that set the standard. For those who may never have read the book or seen the movie, the most romantic bit comes at the end. Juliet takes an herb which makes her appear dead. Romeo thinks she really is dead, so he drinks poison. She awakens and finds him truly dead so stabs herself with his dagger.