If there is a dad in the picture who you want to be very involved, get one that is black, or tan, or grey, not baby looking. My husband had no trouble carrying ours around, it looked like a camera bag, but it might have pressed his buttons if it had been pastel or floral.
Look for one with an insulated compartment for bottles, and with an interior that has some separate areas.
I bought a Carter's and a Graco one, the Graco will be my main one and it's pretty big. Both seem to be good quality and I like them a lot. I suggest looking at BuyBuy Baby, they have very cute diaper bags and they seem much I better quality. I'm thinking about buying another from there lol
Fisher Price one that's green. Best one..using it right now
I use Dakine backpacks. They have squishy shoulders and snap in front. Way better.
I have a diaper backpack that i got at walmartthat's really enjoy except the insulated pocket isvtoo small and won't close with a small bottle in it