J.-B. Zuber offered respectively 1, 2 and 3 bottles of Champagne for the classification of finite quantum subgroups of $SU_q(3)$, $SU_q(4)$, and $SU_q(5)$, respectively.

Ocneanu solved the first two cases, but as far as I know the problem for $SU_q(5)$ is still open.