if you want to go to the zoo. I suggest woodland park zoo
http://www.zoo.org/zoo_info/planning/activities.html
Some good walking and you see the animals in their habitat not so much of a glass box. We went there a few weeks ago. There is also point defiance zoo. I don't remember it well I haven't been there since I was 4. And also hit up Pike Place Market. it's a must see and it's really fun.
http://www.pikeplacemarket.org/frameset.asp?flash=false