I like having visitors because you discover all these cool things in the area that you never knew about. It's as though by virtue of living in Seattle you are both simultaneously supposed to know about and never have been to (or never take the time to go to) “tourist attractions and other oddities”.
For example, the parents are in town this week(ish) and I've now finally been to the Olympic Penisula and visited Port Townsend “the town that epitimizes Victorian sea towns”... It's actually a really cool place with art galleries, small shops, resturaunts and beautiful views of the water, etc. Granted, I somehow doubt the third weekend of October is high-season, so we didn't have to deal with the crowds that are probably there in the summer weekends, and our wait for the ferry to come back Seattle-side of the water wasn't one of the epic three-hour waits. Those things probably would sour you a bit on the whole experience.
Other things that I've seen recently or would like to - the Zoo (not the Zoo Tavern in Eastlake, the Woodland Park Zoo): Clodagh and I went about a month ago and it's actually quite a decent zoo. Boeing musuem of flight - I've now driven by this (on the road next to it, not on the highway where they have the sign) and would really like to go and check out the concorde. Microsoft museum - ok, this one is a bit geeky, but I'd be curious to see what they actually have in it. The list goes on beyond that but the hour gets late and I must head to work...