Washington state
Washington state dashboard (numbers updated at 3 pm daily)
UW Virology Lab testing dashboard
U.S.
CDC tracker for the U.S. (updated daily at noon)
USA Facts: Mapping the COVID-19 Outbreak in the United States
New York Times Coronavirus in the U.S. dashboard
New York Times: states and cities that have told residents to stay home
The COVID Tracking Project (accurate testing numbers for all 50 states)
World
World Health Organization dashboard
Johns Hopkins Coronavirus Resource Center (direct map link here)
University of Virginia COVID-19 Surveillance Dashboard
New York Times Coronavirus Map: Tracking the Global Outbreak
NCOV2019 Coronavirus Dashboard (the one built by the Mercer Island teenager)