I'm very close with all three of my kids (one daughter, two sons). My bond with my daughter is partly shared gender, as we can commiserate on a lot of female issues. With my boys, it seems there are less competitive, if you will, issues of the sort only psychology (and, perhaps, anthropology) can explain. Not that I openly battle with my daughter - not now that's she's 18 and away at school, at least! But my boys are more forgiving of me, more protective, in a way. All three bonds are close but my relationship with my sons seems a bit more tender, for lack of a better word. My daughter's very mature and self-assured, maybe that's it, while my boys are less driven and stick closer to home. All this is individual, of course. Every situation is different. I'm not even sure I answered the question (!) but these are my thoughts.
Lisa