Snow is a good one, but IIRC it ends badly. Its many format imitators can approach goodness, but all the RIs die in the end. Romantic storygames around these parts generally aren't fun, uplifting, or anything other than mature and melancholy, really, to the point where I've been rather jaded by the genre.
But, there is this one. This one's happy and shit:
http://chooseyourstory.com/story/what-do-you-want-to-do-tonight~3f
It's not about falling in love, it's about two people already in love being happy. Which is good enough, I'd guess. It's a happy lovey thing.
Oh, and The Proposal. That's also just peachy.
http://chooseyourstory.com/story/the-proposal
This one's also very innocent and goodly, but really fucking difficult to beat.
If you're into love catharsis, you need only look at the featured stories. There aren't much stories about falling in love here that are happy. I've spoiled basically half the stories in there by saying "she dies in the end".