Commonwealth Lake and Bethany Lake. Both owned by THPRD. Both stocked with trout and panfish and bass. Some nice bass in both lakes. Commonwealth is off Foothill Dr and Huntington in Beaverton. Bethany is at the SW corner of the intersection of 185th and West Union.
And of course there's the Tualatin River in Hillsboro/Sherwood/Tigard/Tualatin...