Standard Process, GreenLife from VE Irons, Carlson Fish Oil... Rotating magnesiums at bedtime. It's my understanding your calcium absorption is a lot better if you take the magnesium separately. At the peak, the nutritionist had me taking close to 60 pills per day. I did not enjoy it, but it is for her and me, so....
I was already taking lots of supplements because I kept taking most of them while breastfeeding our little One.
If there was only one supplement you could take, I would say it's the GreenLife. Met an Amish woman who took it with half of her pregnancies and not with the other half. The difference in her children is amazing.
I do know our little One came out with a full head of hair and holding her own head up. She was scooting herself around on her belly by 6 weeks.
I think diet is just as important as supplements, though.
If you have the time and energy to make sure you always eat perfectly, I don't think there is really any need for them. Things like cooking in cast iron instead of stainless steel or (heaven forbid) teflon help, too.