I enjoy riding in the rain too. My wife doesn't understand it, but she hates walking 15 feet from the driveway to the door in a light sprinkle.

A few things I've found make it much more enjoyable:
Fenders - The rain coming down is clean and refreshing. The muck coming up is nasty and serenity-sucking.
Waterproof Bags - Riding in the rain is fun, but sitting in the office in wet work clothes is not so much.
Temp - Riding in the rain is a lot more enjoyable above 40 degrees. From about 39 down to 32 if it's raining hard it can turn into a hypothermia risk. I'll still ride, but I have to be aware and make appropriate preparations.