Loved the decor - great location!
I absolutely loved the Argonaut Hotel- from the first time I walked in I was greeted by the maritime themed decor and it persisted throughout the hotel. The lobby was cosy, with a fireplace- it can get quite chilly in SF and they have the usual 5-6pm free wine.
The rooms were spacious and the nautical decor was lovely, my fiancee absolutely loved the place. We forgot our toothpaste and room service brought some up free of charge. 
The hotel is located at the start of Fisherman's Wharf and it's easy just to walk out of the hotel and enjoy the sights & sounds of the wharf. There are also nearby bicycle shops to rent bikes to cycle across the golden gate bridge. There is also the cable car station just in the next block so you can take the historic car downtown.
Pros: Great hotel, beautiful, service top notch. Location.
Cons: No bath tub