The best replacement for comma is colon.

The best alternatives to comma are rated as following:
★★★★★  colon
★★★★★  semicolon
★★★  dash
★★★  period
★★  coma
★  colon after dear
★  semi colon
★  semicolon list
★  decimal point
★  oxford comma
  semicolon use
  colon salutation
  semicolon javascript
  semi-colon
  hyphen
  dot
  apostrophe
  em dash
  semicolon after colon
  decimal
  semicolon grammar
  parentheses
  point
  period for decimal point
  semicolons

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

Other search terms related to comma and their ratings are:
★★★★★ but
★★★★ too
★★★★ because
★★★★ and
★★★ such as
★★★ so
★★ however
★★ as well as
★★ which
★★ or
★ including
★ therefore
★ while
★ conjunction
since
though
two adjectives
thus
an introductory phrase
then
especially
You have in mind a companion for comma and it is not yet here? Propose!



Google Trends

Scale is based on the average worldwide traffic of comma in all years. Click on graph for more.
comma
colon
semicolon