I always tried to help the Fallen and Cabal against the Hive since they're pretty much pure evil. I know it doesn't mean anything because it's a game and they won't notice and they'll just keep respawning, but I don't know. I always felt for the Cabal after reading that grimoire or flavor text (can't remember where I read it) about them being regular soldiers weary from months of deployment. Just going where they're told to go; waiting to go home and see their families. Humanizes them somewhat. Always thought it'd be cool to find myself pinned down back to back with a squad of Cabal and fight to the end. Same with Fallen really.