Thrust.

You're forgetting the huge disadvantage of stun causing gobies to fall to the bottom.

I meant pure DPS on Fire-Strong mobs =P

As I recall, .75 is only possible for attacks with 2 elements (Comp) where the monster is only resistant to one of them. so then the figure would be .5. :/

Actually, Inferno and Blizzard have a halved Elemental Advantage/Resistance. Max is 1.25 on Fire-Weak, .75 on Fire-Resistant (for Inferno, replace Fire with Ice for Blizzard).
Russt just doesn't know whether the tests that showed Inferno at optimal efficiency vs Fire-Resistant monsters was done with the outdated knowledge that it was .5 damage, or the more recently aqcuired data of it being .75

Edit: It's outdated. Inferno level 30 is 142.5% Average Damage per hit on Fire-Resistant, while level 22 is 136.7% =P