I can't believe I forgot about Crazyhorse. I used to be friends with the contractor who built their stage. You can't go wrong with Crazyhorse, also Centerfolds is 18 and up. One thing about centerfolds and crazyhorse, they are strickly legit, so if you are looking for whores, go elsewhere.
This <a href="http://www.sanfrancisco-strip-clubs.com/strip_club_list.asp?NavCityID=108&NavStateCode=CA" target="_blank">site</a> has a listing of stripclubs in the city, any that don't serve alcohol should be 18 and up. The Gold Club is 21 and up so you're too young to go there.
<a href="http://www.sanfrancisco-strip-clubs.com/the_strip_club_list.asp" target="_blank">For the rest of you looking for stripclubs, this site has a directory of clubs in the States.</a>