Lists also tend not to do so well as submissions because there isn't that much that's interesting to discuss—just the lowest common denominator of the items on the list. It's generally better to pick the most interesting item on the list and submit that instead.
- Hanabi is now the "frontier of AI research" with both FB/DeepMind working on it
- Magic the Gathering is Turing complete
- Kingdomino is NP-hard
- There is published endgame research for RISK (similar to how you have endtables in chess)
- There's a lot of interesting research on catan and monopoly. Monopoly seems to have a lot of research around teaching language-skills to kids, in particular.
- There is research on generating new maps for Ticket to Ride!
- Lots of interesting research on 2048, the mobile game.
- There is a mathematical model for Mafia.