What kind of cuisines do you want to try out? I know a good Burmese restaurant in north Oakland (also has a branch in SF) and an interesting little Indian food place in the Castro. Very different and not your typical Indian restaurant with a buffet. There are definitely some good restaurants to try out if you are into Asian cuisine. For seafood, Fisherman's wharf is the place to be. Also check out the sea lions and other touristy stuff....And are you the clubbing type? If so, there are some posh clubs near AT&T park. But I would really recommend checking out the Mission. Especially around 16th street and Mission street. Easily accessible by BART.
Here is the link for the Burmese place:
http://www.burmasuperstar.com/Also this is the Indian place:
http://www.kasaindian.com/Let me know what other cuisines interest you or what your other interests may be. I would recommend checking out Telegraph Avenue in Berkeley too...again easily accessible by BART.