For sheer daydreams, I've been enjoying an A/B/O AU As the Summer Rains Fall. It's delightfully overwrought and melodramatic, and it is one of those stories that I'll happily daydream different scenarios for -- how I would write a happy end here, or extra angst there. Not stories I'd ever write or could make work as a serious narrative, but daydreams I indulge in or stories I tell myself as I'm falling asleep.