Good spot for walking around
I was in San Fran for a few days on a work trip and we were staying at Le Meridien. I had never stayed at one of their hotels and was pleasantly surprised. The staff was extremely friendly and my room (which was upgraded to a suite) had a king sized bed, an office and sitting room, and a nice big bathroom. 
Most importantly, it was in a great spot to be able to get around the city. It's in the financial district and was a $5 cab ride from the Moscone convention center for those in on business. If you're there for pleasure, walk two blocks and you'll run into the ferry building (a must see) or go a little further down and hit the fisherman's wharf area. 
A cool hotel in a great spot!