Instead of listing a million love letters for you to try to comb through, I've separated the wheat from the chaff. The love letters on this page are the best of the best.
Now, more than likely, no one letter is going to be perfect for you to copy verbatim. This is a good thing though, because nobody wants to receive a love letter that was completely written by someone else.
Instead, use these real love letters as a jumping off point. Certain romantic phrases are timeless and universal. These are great love letters to read, so, peruse through and pick a few sweet lines here and there to build off of. But, make sure to inject your unique style into your finished product so your lover can cherish it as a true example of how you feel.