There are many things to do in Oakland. The biggest development in the past handful of years is that one of the top restaurant scenes in the US is taking place in Oakland. Although decent lodging is sparse, if you stay at City Center (There is a Marriott), you can be in downtown SF in under 15 minutes on BART.

Oakland's Chinatown is a lot more "real" than SF (well, as far as there is no "tourist central" section). There are a handful of urban wineries in/near downtown/Jack London Sq. area - they are good to very good. See if anything is playing at the Paramount - a fantastic theater. The architecture of many downtown to uptown buildings is really great - on a building by building level - if you drive through, you'll never notice. If you will be there on the first weekend of a month, there's a big street art/food festival every month - http://oaklandartmurmur.org/

That is just a small list of things that quickly come to mind as I get ready for work.