i tend to agree with Sdfsdfsdfsdfsdfsdf (above).
From the few times i visited SF, it seemed to have some cultural energy that far exceeds that which i find here in Seattle. But SF to me, by comparison was really huge, and crowded, and a bit unmanageable. The two cities are very different beasts when you consider size and culture.
Seattle is really quite beautiful. There are incredible views even from within vast portions of the city. The Puget Sound is nice and the San Juans and Lopez, etc. are right across the sound and very accessible by ferry. There's mountains to the east and mountains to the west, with lots of great outdoor stuff within easy drives.
The complaints about the weather are nonsense, frankly. Yes, it rains here a lot during the winter, but the rain is in lieu of snow most other places. It's generally a drizzle several times a day, but not downpours usually. And the summer is amazing, and is actually arid for 3 or 4 months each year (very little rainfall that time of year). And it is not too hot unlike a lot of other places.
Every time i went to SF, it was generally very chilly., esp. mornings. I bet there is less difference in weather between the two than you think.
For me, if i was really into an active social scene, SF has the edge by a long shot. Seattle seems to me better for those people who like to do their own thing, and it has a bit of a reputation for being a bit standoff-ish. Not unfriendly, but not all that outgoing, either.