Regicide (inspired by Age of Empires): Two teams compete fighting from different houses/forts/castles/cities/sides of a river/whatever the fuck I decide to make the map, with the sole goal of keeping one specific player on their team alive. This player is dubbed their king (or whatever the fuck I decide to name him i.e. Autist, Virgin, Bitchbaby, etc). Victory is awarded to the team who keeps their king alive longer than the other team; if your king dies you lose, if their king dies they lose. Theres a lot of fun variables to consider, for example we could allow all the players on each team that aren't kings to respawn so its like a deathmatch to kill the enemy king.
This sound pretty dope. If any of the devs got behind this enough to make it an official game type, I'm sure they could code it so that the player who is his/her team's king has the crowned helmet/crown on whatever headwear they are using... that would be amusing.
In terms of maps, you'd probably want to make these maps arena-like (symmetrical, think the size of most competitive Halo maps) so that the teams are fair. I imagine something like two keeps with walls in between. Nothing big. A big problem with cRPG in the past has been slow gameplaying or delaying. This should be a quick, intense game.