We stayed at the Contemporary on our first trip with our kids. My son was 4 and my daughter was only 6 months at the time (10/95). We had a garden room and I can't say enough how convenient it was.
My kids were both early risers, so we arrived at the parks early stayed until mid-day then came back for naptime. We were all refreshed when we went back to the parks in the afternoon and evening.
That was only a three day trip so we just did MK & Epcot using Monorail of course (which my son LOVED!). We did things at THEIR pace. My husband and I had been once together without kids and we couldn't believe all of the "screaming me-mes" everywhere. Kids were miserable and parents were miserable. It was obvious that they were of the "I-paid-all-this-money-and-you're-going-to-do-everything-so-I-get-my-money's-worth-even-if-it-kills-me" mindset.
Studios was open but we didn't want to get on a bus with a stroller and thought we'd wait until the kids were older to see that.
I have a picture of my 6 month old kissing Mickey on the cheek! (sniff sniff)
She's now 13 and we're heaing back two weeks for her 6th trip in!
We also stayed at the Polynesian when they were DS10 and DD6. That was also nice because we actually did some pool time there in the afternoon, but we could still see the castle from the big pool area. The kids realized we were still so close. And it is really neat to watch the fireworks from the Poly's beach area. When we were there we stayed at Epcot for Illuminations one night. We were in our room getting ready for bed and heard popping noises. We looked out and there was a fireworks show going off at MK. MK was closed at the time, so we figured it must have been a private function (in February). So we got the kids up and all of us in our PJs were on the side balcony of the longhouse by the stairs watching the fireworks show!!! The kids ooed and ahhed. It was pretty cool!!! (We could also hear the howling dogs from the Haunted Mansion at night. The kids got a kick out of that, too!) (We were there in Feb '02 right after Disney dropped rates big time to increase tourism after 9/11.)
Anyway, here's another vote for a monorail resort. I would also suggest that you not make it a week long trip. Shorter trips are more affordable for staying at monorail resorts and also more doable for a baby/toddler.
Allison