As I recall after extensive research Hera concluded the answer was women. I don't see any reason to dispute this, but it does seem not to have been capitalized upon in the remainder of the myths.

According to Greek mythology the prophet Tiresias lived first as a man then was turned into a woman for seven years only to be turned again back into a man. Afterwards, Tiresius was asked to settle a dispute between Zeus and his wife Hera as to which gender enjoyed sex the most. Tiresias replied that there was no contest: it was ten times greater for a woman. This answer infuriated Hera who struck Teresias blind for his insolence; Zeus however in compensation gave him the gift of foresight. 

Fascinating. Do you or anyone else have any insight into this myth -- why the anger, why those specific gifts/curses? Surely they are related to the story, and not just in the ironic sense of "here's some foresight since you should have seen what you were getting into with that answer."