http://web.stanford.edu/class/cs166/handouts/100%20Suggested%20Final%20Project%20Topics.pdf
Some of the ones listed are somewhat par for the course for advanced CP'ers (Range Queries, RMQ for LCA, Suffix Automaton, Ukkonen's Algorithm), but most of them are ones I've never heard about.
In addition to describing the data structure, they also give a "Why they're worth studying". Pretty cool!