I'd like to add Northern Exposure to this list. It was definitely a liberal-leaning sort of show, but it often investigated both sides of philosophical debates in a way I've never seen on network TV.
As for the West Wing, it had its moments, but it was essentially an extended liberal wet dream, where the president is a New England liberal who also relates to the common man, always wins when he goes up against congress, and kicks the faceless Republican's ass in the debate. Yawn...