The best replacement for arial is helvetica.

The best alternatives to arial are rated as following:
★★★★★  helvetica
★★★★  times new roman
★★★  verdana
★★★  calibri
★★  aerial
★  tahoma
★  arial mt
★  arial unicode ms
★  calibri font
  ariel
  courier
  arial unicode
  times
  arial narrow
  open sans
  arialmt
  segoe ui
  century gothic
  garamond
  trebuchet ms
  myriad pro
  sans-serif
  new times roman
  trebuchet
  cambria
  futura
  courier new
  times roman

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

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



Google Trends

Scale is based on the average worldwide traffic of arial in all years. Click on graph for more.
arial
helvetica
times new roman