The best replacement for sans is serif.

The best alternatives to sans are rated as following:
★★★★★  serif
★★  ec council
★★  san
★★  ceh
★  offensive security
★  avec
★  giac
★  infosec institute
  helvetica
  source sans pro
  owasp
  chalkboard
  pans
  sans

Your alternative for sans is not listed? Suggest!
Speaking about sans, one probably shouldn't forget about serif.

Other search terms related to sans and their ratings are:
★★★★★ serif
You have in mind a companion for sans and it is not yet here? Propose!



Google Trends

Scale is based on the average worldwide traffic of sans in all years. Click on graph for more.
sans
serif
ec council