So me and 8 of my friends played Defenders of the Realm board game tonight. Hard as hell, but we won! Half of us had never played before.
The goal of this cooperative game is to keep four enemy factions away from the capital. You must defeat all four generals to win the game. There are many many different classes with unique abilities, and the game forces you to think on your feet, because enemies spawn almost every turn and stagnation on the game board will also end the game. Each general has special abilities, and have chances to regenerate health. Each characters are also given quests to fulfill that can grant powerful bonuses or one-time powers that come in handy later towards the game.
It's not at all affordable, however, as I think you can maybe get it for $80+ now. Also you need at least 4 hrs to play for a large group. But I heartily recommend this game if they can gain access to it.