I don't think there is a perfect gap, it's just what works for you. my two boys are 16 months apart and although it was very hard for the first 4 months or so, it is fantastic and we are really enjoyinging having two so close. i think a great age gap is between 16 and 20 months. ds1 coped really well when ds2 came along, but i think if he'd come along now (while ds1 is 2.5yrs old) it may have been a different story.