Families with kids are the core of WDW's business, so all of Disney's resorts cater to babies and toddlers. There's no one that's overall "best" in that regard, it's more a matter of what's best for your family and your vacation plans.
I'd start with budget, and narrow down your resort choices from there. Who's going? How many people will be in the room? The mix of adults/kids? There are all sorts of sleeping arrangements at various resorts. Queen, king, sofabeds, daybeds, murphy beds, etc. Family suites and villas with separate bedrooms.
Then, think about your plans. Where are you going to be spending most of your time? Are you focusing on one park, maybe MK? Or do you plan to divide your time between all of the parks? What kind of transportation do you prefer? Monorail, boats, buses? Or do you want to be able to walk to one or more parks?
Once that's nailed down, look at each resort's amenities. Do you prefer food court-style dining? Table service? Do you want to be able to order room service? How about recreation? Are you good with a pool and a kiddie play area/splash pad? Or do you want more recreation options, like boat rentals?
And then, of course, there's theming to consider if that's important to you. Do you want in-your-face Disney, the French Quarter, a tropical resort, a New England-style beach resort, the Pacific Northwest?
Lots to think about, I know.

Let us know the answers to some of those questions and you'll get loads of suggestions.