The most interesting opinion/analysis writer at work these days is perhaps David Gardner in the Financial Times. The latest one on Spain is really excellent. The demolition of the US "strategy" in Iraq from a few weeks ago is required reading.
UPDATE 25 NOVEMBER: Beginning almost immediately after we wrote the above, there seemed to be no more Gardner in the analysis page. It turns out he got bumped up to chief leader writer, meaning that one has to now read the FT editorials and discern his touch. He's still doing the occasional book review.