I'd go for some really lovely PJs/loungewear for when you are home so you don't feel too manky. I also got some nice sweaty Betty high waisted leggings and a nice oversized jumper which were comfy/easy to throw on but made me feel nice.
A bottle of really lovely wine/champagne?
The M&S bralettes are fab for breastfeeding.
A mattress topper? My lovely mattress now has milk stains all over it from my insane boobs.
Some great smelling shower gel/bath stuff for your first bath or shower?
Agree with the pp who said dried fruit. It's not as delicious as chocolate but dried apricots will help the first post baby poop!
Really boring, but in the hospital they make you write down every time your baby poos/wees/feeds. So a note book for your bag with a pen.
A copy of 'Your baby week by week'. The best book out there in my opinion.
A list of breastfeeding support numbers ready to go.
Some films downloaded/tv box sets that you are looking forward to watching.