We got a big wide Ryco one. It has a front pocket with compartments, a bottle warmer hole, a big slide zip and a change mat attached to the back. DD1 was only 21 months when DD2 was born so it meant lots of nappies. I think I just got it from Target or Kmart and it has plenty of room for 2 kids stuff. DD1 still uses her Barbie bag whenever she goes somewhere by herself like daycare, so I just keep a spare change of clothes and a couple of nappies with a small pack of wipes in it.