HAL has the best Western Washington airports nailed! Friday Harbor (FHR) is the premier weekend warrior GA destination. But the one that takes the cake is Copalis Beach (S16). It's a chunk of beach on the Pacific Coast that is designated as a state airport. Preflight planning should probably include checking the tide tables. The damp sand is firmer than you might think. You can grab lunch at HQM which is just a short hop away.
Ranger Creek (6WA8)- great spot if you're mountain flying skills are up. Bring your camera, plus camping gear, hiking boots, mountain bikes, etc. May need to buzz the strip to warn the dirt-bikers you're coming in.
As for Firstair in Monroe, WA, you can also hop over to Sky Harbor (WA64) which is 1900' of grass boxed in with trees on one side. There's some neat planes there (Cubs, Widgeons, projects going on, etc).
In Central Ohio, Packer (5E9) is a couple well-groomed grass strips with Avgas and tons of cool planes. On a nice day you might see a Twin Beech, Stearmans, T-6's, Pitts Specials, Cubs, or who knows what.
Also south of Dayton is Stewart(401) in Waynesville - they've also got Avgas plus Cubs, Stearmans, and other neat planes.
Blue Skies!
Wang