The best replacement for mapquest is google maps.

The best alternatives to mapquest are rated as following:
★★★★★  google maps
★★  waze
★  yahoo maps
★  openstreetmap
★  apple maps
  bing maps
  maps
  telenav
  cloudmade
  google map
  other maps

Your alternative for mapquest is not listed? Suggest!
Speaking about mapquest, one probably shouldn't forget about gas cost.

Other search terms related to mapquest and their ratings are:
★★★★★ gas cost
★★★★★ driving directions
★★★ directions
★ voice directions
★ highway directions
freeway directions
You have in mind a companion for mapquest and it is not yet here? Propose!



Google Trends

Scale is based on the average worldwide traffic of mapquest in all years. Click on graph for more.
mapquest
google maps
waze