Is everyone interested in the Battle tournament? I think either that or Dance of Dragons sounds the most fun for our buck. Diplomacy is great but the way I do it makes it pretty intense.
Dance is smaller in terms of available factions but there are some very interesting characters; Aegon and Rhaenyra, the sea snake, Daemon, Lord Boremund, Otto Hightower, Larys the Clubfoot...
Meanwhile the Battle tournament is a very achievable goal with a definite end. 6-8 players, meaning a Max of seven or so battles to judge.
Well, to be honest I am more interested in a Dance game.