this one isnt a proper sample to be the real grind(skips it in trailer), but this is the woman who can actually do a reverse cowgirl grind sitting straight up!
also i havent seen too many others from this site, but until i do, my opinion stays with her...
janine(woman with godlike grinding skill)
http://creampiethais.com/z_tour/janine/
some clips of her, unfortunately no grinding action! but hot anyway!
http://www.foreignporn.com/thai/janine/legs.html