Jörg Knappen wrote on Wed, Dec 8, 2010 03:16 PM EST:
First, look at the recognised chess variants here:
http://www.chessvariants.org/rindex.html
Then, all national chess variants with a player community and some
tradition; i.e., Makruk, Sittuyin, Shatar (Mongolian Chess).
You may also look at contest-winning chess variants and contest finalists,
see here:
http://www.chessvariants.org/index/mainquery.php?type=Contest&orderby=LinkText&displayauthor=1&displayinventor=1&usethisheading=Contests