Alviso is a decent spot when the sunset looks like it's going to be good. It isn't more than a ten minute drive from my house, so I can easily make it there on short notice.
The Pipiwai Trail is a nice hike in Haleakala National Park that includes a dense bamboo forest
Multnomah Falls is a spectacular waterfall in the Columbia River Gorge and is the tallest in all of Oregon.