Well, assuming all the forces of the Destiny universe were on the same side and worked together, I'd say the Destiny universe. Granted i don't actually know much about the DC or the Marvel universes, but it seems like to me the ability to take people and turn them into your slaves (taken superman and or hulk. Picture that), the ability to resurrect people from death, and the Vex's ability to infect almost anyone and simulate people with extreme precision (of course this probably wouldn't work on the more cosmic entities) would really turn the tide of battle. Not to mention we don't know the full extent of the Deep or the Traveler's powers, or even what kind of abilities the other Worm Gods have.