My personal favorite at St. Marks is actually a CNM, Danielle Demeter. She is fantastic.
Lots of women seem to love Eric Nielson, he is a very fine doctor, gentle and respectful, but he does have an odd gum chewing habit! The other doctor and CNMs that are in his practice also have good reputations, but I have not worked with them.
Darren Watts and Vernon Yamishiro have good reputations also, but I can't speak to them personally.
St. Marks is not a mother/baby friendly hospital, they tend to separate babes and moms more often than some other hospitals, you might want to keep that in mind also.
Good luck!!
PS - I see others recommend Dr. Wheeler and Dr. Lamb. She no longer does OB, and I don't recommend Lamb.