If your budget can stretch to it I'd say a thermomix. I'm seriously lusting after one myself. You get the benefit of being able to cook the food and then puree it all in the one thing so quick with time and minimal washing up. In the past my "machine" has been a potato masher

I was chatting with girlfriends the other day about "push presents" and how they're supposedly the latest thing with jewellery seeming to be an "appropriate" present after giving birth. Personally, I'm happy with a healthy baby but my wish list for a push present would be a thermomix or a stokke! Much more useful than a pair of diamond earrings ;-)