There a few writers/columnists/authors that I read faithfully, whenever they appear in the many newspapers/magazines I scan. They are not all liberal leaning, but these tend to be the most-entertaining. I have found only one conservative writer to interest me (P.J. O'Rourke); the rest are too rabid.
Here's a partial list:
Simon Jenkins (Guardian, London Times, other)
Gail Collins (New York Times)
Frank Rich (New York Times)
Maureen Dowd (New York Times)
Hadley Freeman (Guardian)
Julie Burchill (currently Independent, but changes)
Theodore Dalrymple (various UK publications, pseudonym of a physician)
Marina Hyde (guardian)
Several New Yorker writers
The writing, depending upon the individual and/or topic, is always intelligent, bold, irreverent, humorous, honest, insightful, and always well-written. Each informs, provokes thought, and entertains. Sometimes, the topic covered makes me angry, so I do not read beyond the headline. It's not the writer's fault individuals or story that they cover are so distasteful. Many topics do not interest me, but good writing forces me to read to the end.