The Max runs all the way to Hillsboro (West of Portland) and Gresham (East of Portland) and typically runs until 11pm. A good option for folks staying in the Suburbs. Make sure to check how close your hotel/accommodations are to the line to ensure you don't have far to walk! https://trimet.org/max/index.htm
Uber and Lyft are available in Portland, and are good options if you are looking for a quick ride back to your hotel in the city. A little spendier if you are commuting back to the suburbs, but not bad in the city.