HANDS DOWN, the best stylish non baby looking diaper bag is from VERA BRADLEY. I have have had numerous diaper bags looking for THE ONE that met all my needs, and without question, Vera Bradley is the best.
I also have a Coach diaper bag, and while it is a super nice bag, it is super heavy, and doesn't have all the neat compartments and stuff that I wanted. Plus the straps don't slip over my shoulder easily, as they are a little too short. I may eventually use it for a tote or something, but NOT the best diaper bag.
I have also tried other diaper bags, and none compared to the stylish, fun, colorful, lightweight versatility of the Vera Bradely bags. VB does make an actual Baby Bag:
http://www.verabradley.com/Site/Store/ProductDetail.aspx?...
which might be the best choice if you don't have a changing pad, etc., but both I and a cousin of mine swear by the "Vera" which we use as a diaper bag, a tote, basically a carry-all of sorts that will take you way beyond your diaper bag years! You would just have to supply your own changing pad... Otherwise, it has 4 interior pockets that perfectly fit bottles or sippee cups, and other pockets for organizing, as well as a longer handle that fits easily over the shoulder, and a roomy interior for all the essentials. Plus, they have matching wallets, and tons of other accessories. And it's machine washable!! Does it get any better? Here's the link to the Vera...
http://www.verabradley.com/Site/Store/ProductDetail.aspx?...
They are not inexpensive so to speak, but they are worth every penny... and they last forever.
Hope you try one and enjoy it as much as I do! The only problem is once you have one, you might get hooked... they are kind of addictive, with the new prints each season... lol :)
And no, I am not a VB retailer! Just a very satisfied customer... :)
Oh, and if you buy one of the retiring colors, you can get those at a pretty nice discount! Can you tell I've done this before? lol
Best of luck finding a diaper bag that suits you! It's something you spend a lot of time with in the first few years, as you know!