Child's Glacier is certainly Alaska's most spectacular roadside glacier--it's the only one where you can see calving. Child's Glacier is 400 yards across the river from the viewing platform, so you can't walk up to it like you can Exit, Byron, or Matanuska Glaciers.
Directions: Cordova is an hour flight from Anchorage. Then, it's a 1 hr drive to the glacier.
Distance: 190 miles east of Anchorage
Drive Time: 3 hours
Explore: If you visit Cordova, make a day out of exploring the Copper River Highway (which ends at the glacier), Child's Glacier itself, and the nearby Million Dollar Bridge.