There are a lot of classic romance novels I've read in English. I am, of course, all too familiar with Austen's novels, but one of the things I am familiar with which I recommend you read would be Alexandre Dumas' fil's The Lady of the Camellias, which was the inspiration for the opera La Traviata. You can, of course, find it online for free. I would also recommend Longus' Daphnis and Chloe - another great classic from Ancient Greece - Venus and Adonis by Shakespeare, John Fowles' The French Lieutenant's Woman, Richardson's Pamela, Metiochus and Parthenope and Thomas Hardy's Far From the Madding Crowd.
These are the only examples I've been able to come up with so far, but there's an entire wealth of love stories from both the English and Greco-Latin-speaking worlds, and if I remember any more of them, I'll let you know. I would also recommend at least half of the stories in Ovid's Metamorphoses, since they at least deal with doomed romances.
