Hood Drainage: Dee to Tucker (III/IV), West Fork (IV), Lake Branch of WF(IV/V) should be good. Dee to Tucker is pretty much a class III run until the last mile or so, then some of the rapids earn a class IV rating. West Fork, as said in Bennett's guide, is classic class IV Oregon whitewater. It's a hoot! The Lake Branch of the WF is fun as well, but you need higher flows. There are a few wood portages, but it's a great run.
White Salmon: Middle WS good class III run which can be run almost at any flow. Farmlands, great class IV/IV+ run. Look for flows of atleast 2.5 if not 3' on the Husum Gauge.
Upper Wind (at lower levels) is a good class IV/IV+ run. I've only run this at low and medium/low flows. It's fun in both a creekboat and a playboat.