If you want to be close to Chinatown or Union Square in San Francisco, then the Worldmark San Francisco is a great choice. I stayed in the studio hotel which was cozy, but had everything I needed (since I carry a electric Skillet). There was a gym and a shared laundry facility, which was nice for a city based timeshare.
The proximity to the central parts of the City was a plus… The fact that the parking garage is right across the street ($44/night) is a plus. Check in was easy because there is an unloading zone. The staff was really helpful and friendly. At a cost of $100/night, that is an amazing deal for downtown San Francisco where some hotels can exceed $500/night easily.