There are plenty of ranges to choose from. I guess it depends on the style you are after.

I recently purchased an Oi Oi nappy bag (baby due July so haven't used it yet) but I loved it.

Here are a few other brands you can have a look at it:

Kapoochi
Airport Luggage Collection Mothers Bag
gr8x
Isoki


There are plenty to choose from - Good Luck with your choice.