The Iconic powers Heat Vision - Frost Breath - Batarangs - Gag Glove - Sonic Shout - Neo Venom Boost no contest.
Depends on the player really. Sadly Electric and Nature are a different story. Doesn't matter how good you are with the powers you'll be under-performing in dps role.
The best DPS in DCUO is nature. This is because the nature power consist of having multiple options when creating the DPS. The loadout for this soecific power allows to use certains forms lika canine and wollf form which can allow players to consider using more than one DPS