The best replacement for plaid is tartan.

The best alternatives to plaid are rated as following:
★★★★★  tartan
★★★★★  flannel
★★★  checkered
★★★  check
★★  stripes
★★  gingham
★★  paisley
★  argyle
★  plad
★  played
★  madras
  flannel shirts
  please me
  houndstooth
  floral
  checks

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

Other search terms related to plaid and their ratings are:
★★★★★ stripes
★★★★ polka dots
★★★★ argyle
★★★ plaid
★★ floral
★ corduroy
★ pinstripes
stripes einstein
You have in mind a companion for plaid and it is not yet here? Propose!



Google Trends

Scale is based on the average worldwide traffic of plaid in all years. Click on graph for more.
plaid
tartan
flannel