crysis 3 has so many things to offer. how sweet would it be if any1 could join the your room from a lobby with your own custom match setting.
and if you truely wanted a private room make your room set a password / or make it invite only.
game that i can think of really quick that do this. the game that has done this the best would be mgo(metal gear online). i think battlefield 3 does something like this but u have to play to host