The best replacement for dado is router.

The best alternatives to dado are rated as following:
★★★★★  router
★★★★  rabbet
★★  pocket screw
★  mortise
★  dovetail
★  joao gordo
★  groove
★  gordo
  dato
  router dado
  stacked dado

Your alternative for dado is not listed? Suggest!
Speaking about dado, one probably shouldn't forget about table saw.

Other search terms related to dado and their ratings are:
★★★★★ table saw
★★ radial arm saw
★ dw745
You have in mind a companion for dado and it is not yet here? Propose!



Google Trends

Scale is based on the average worldwide traffic of dado in all years. Click on graph for more.
dado
router
rabbet