I'd move Memphis to Seattle.
Memphis has never really embraced the team since it moved from Vancouver. And Seattle ought to have a franchise. That city loves hoops.
Returning the Griz to the Pacific Northwest would help balance out the NW Division. Oklahoma City could then move to the SW Division, where it belongs.
Lastly, I think the historic Portland-Seattle rivalry would be re-energized by two rosters filled with young, up-and-coming, talented players.