In my opinion, an infant seat ia a MUST. It allows you to get a few things done while your baby relaxes right beside you. It's also good for feeding your baby if you don't have or want to use a Boppy. I had the Fisher-Price Baby Papasan Infant Seat and I LOVED it. (This was another gift from my lovely, all knowing, sister)
Highlights include soft and cushy fabrics to cuddle your baby (including a micro suede pillow for baby's head) and this chair VIBRATES!!! (That has to be the best feature) It also plays soothing music, either classic or lullaby (10 songs in all). The music plays continuously for 15 minutes and there is a volume adjustment.
This is definitely one of my "must haves" when it comes to a new baby.