I voted 26-30, because I feel like that's when the majority of people are prepared financially, mentally, and physically to do so.
I'm 23 and own my own house, have a degree, great job which will offer free childcare, and will be married in the next 5 months. I don't think that most people who are my age are as ready as I feel I am, but I've always been different in that way.
We will start trying just after my 24th birthday. My OH will be 25.