So hard to choose... they both have their pros and cons.
I looooove snow while it's snowing, especially at night because the contrast is soo beautiful, and everything is sparkly and there's something just magical in watching it fall while everything around you is completely dark and silent and serene... but I HATE snow the day after. As soon as it starts to get brown and slushy or melty and I have to commute, I want it GONEEE! Those giant mounds in the parking lot that last 'til May get on my nerves.
And rain... rain is sooo good on a warm summer night, especially if you've had a few drinks and you go for a little barefoot walk... then you come in, get all dry and cozy in bed, and wake up in the morning and it's all grey and you listen to it tapping against the window and you just want to stay in bed like that foreverrrrrr. The again, those days when it just goes on and on, sometimes it's not even raining anymore - it's more like an old man wheezing on the back of your neck... and then people's driving skills decrease proportionately to the increase in precipitation... ughh....
So I guess I'd have to say both!