Here will be a list of yaku, especially those that occur in many games. I expect they will eventually be alphabetized (by English or Japanese?), with links to individual pages, which themselves can give details on any alternative names, the contents of the yaku, cultural significance of the imagery in the combination, and further links to games utilizing those yaku.
Animals (Tane)
Boar-Deer-Butterfly (猪鹿蝶 [いのしかちょう, Ino–Shika–Chō])
Flower Viewing (花見酒 [はなみざけ, Hanami-Zake])
Moon Viewing (月見酒 [つきみざけ, Tsukimi-Zake])
Poetry Ribbons (Aka-Tan)
Purple Ribbons (Ao-Tan)
Ribbons (Tanzaku)