Lets think of some Achievements/Trophies that you think would be cool to go for, and would bring out the way Brink is meant to be played.
Team Player
Finish a game with the highest amount of XP and lowest amount of kills.
Enemies like these
Play a full 16 player game with people on your friends list.
Tag Team
Play through one campaign with one or more friend.
Objective Perspective
Finish both campaigns.
Enemy Territory
Master the role of Operative
Unsung Hero
Master the role of Medic
Cream Gravy!
Master the role of Engineer
Caused a 'Quake
Master the role of Soldier
Thats what I got, what cn you come up with?