Jay,
what kinds of things are you interested in? For vistas, you can drive up to Hurricane Ridge in Olympic NP and get great views across the Straight to Canada and east across the Sound. Panorama Point on Mt. Rainier is also fabulous, on a clear day you can see St. Helens and Mt. Adams, maybe even Mt. Hood, but it's hardly a kid friendly hike. There are lots of trails around Paradise, but it can get really busy there (especially on weekends), so try to go early. And Rainier can be clouded in at any time, so watch the weather reports to try to find a good day.