I would have to agree with the Boardwalk Inn. Also, I have heard from friends that the Yacht Club is nice, as long as you stay away from the Beach Club part.
Personally, we liked PO-R, the bayou rooms... we saw and heard very few kids there.
WL was teaming with kids, as was the Contemporary, but the only place we really saw the kids at the Contemporary was in the lobby, or Chef Mickey's. We were in the South Wing, over looking Bay Lake, and it was very quiet, and restful!
Another suggestion would be the Polynesian.
GF is upscale, but you will see the kids... I have never seen any rowdy ones, though!