One would expect that the bottles designed by a company best known for their breastpumps would be ideal for breastfed babies — and Medela's Calma bottles ($17) are. The bottles unique nipple — it is longer and flatter than most others on the market — requires babies to use the same sucking motion used when breastfeeding in order to create a vacuum to release milk. Though the nipple has several pieces to assemble before it is placed on the bottle, users say it is worth the extra steps.