Is it more common for an enemy in CoH/CoV to resist energy or negative energy damage types? Understandably each group will have their own resistances but when looking at the overall trends for the game, which is resisted less?
There are a ton of enemy groups in COH, but luckily someone did the bulk of our work for us. AWhile back someone compiled the average damage done by each damage type: http://boards.cityofheroes.com/showthread.php?t=115749
Looking at that chart, it seems like (except for a few dark magic groups) Negative Energy is where enemies have the least resistance against.
But, IIRC the energy powers in the game also usually utilize the Knockback and Smashing damage types as well, and only a very small amount of enemies have resistance to that.