The San Francisco Chronicle isn't quite a world-class newspaper, but it's better than the city's other daily, The Examiner. So even though the Examiner is free, I usually buy the Chronicle, at least on Mondays through Fridays. (Saturday's paper is very thin, and the Sunday paper, costing $1.50, is mostly ads.)
Like most (all?) newspapers, the Chronicle is going through hard financial times, and has had to lay off many writers. For someone like me who loves newspapers, this is very sad.
They still have a lot of good columnists though. My favorites are Tim Goodman on TV, Mick LaSalle on movies, and Jon Carroll on whatever strikes his fancy. I love the political cartoon "Bad Reporter" by Don Asmussen. They also have a good line-up of syndicated columns and cartoons.
Their website, sfgate.com, is excellent.