What are the biggest/nicest mall in San Francisco?

Westfield San Francisco Center is the nicest one in SF. It just opened last September and it has a Bloomingdales in it. The mall is on Market Street, next to Nordstrom. Once you are in that area, you are pretty much close to all the shopping places like Union Square and Macy's.

Enjoy your day shopping!

Just go to union square. It's not a mall and that's what makes it wonderful. The shopping is amazing too.
If you really need a MALL then the only one I know of is in the Sunset district near SF State. Take the M train (muni) and it will drop you off right in front.

their is a big mall in down town Sf the macys is three stories high

The Westfield Mall in downtown is pretty big.... it's connected to Nordstrom.