Best and worst baby items!

Teri • 24 YO - Engaged 31/12/14 - off Birth Control 28/03/15 - BFP 10/08/15 - Due 22/04/16. Swenglish baby!
Hi ladies, just a fun post to help out a first time mum! What was the best baby purchase you made that you absolutely can't live without and your worst?