Damage them:
Guristas - Kinetic / Thermal
Serpentis - Thermal / Kinetic
Blood Raider - Thermal / EM
Sansha's Nation - EM / Thermal
Angel Cartel - Kinetic / Explosive / Thermal
Minmatar Fleet - Thermal / Explosive
Amarr Navy - EM / Thermal
Gallente - Kinetic / Thermal
Mordu's Legion - EM / Kinetic / Thermal
Mercenaries - Kinetic / Thermal / Explosive
Rogue Drones - ALL Damage Types
Centum - Exp

They shoot:
Angel - EM(shields)/Exp(Armor) & Thermal
Amarr Navy - EM(shield)/Exp(Armor)
Mordus - EM(shield)/Exp(Armor)
Gurista - EM(shields)/Exp(Armor)/Therm & Kinetic
Blood - Therm
Sansha - EM
Serpentis - Therm

stacking penalties:
1st mod: = 100,000%
2nd mod: = 86,912%
3rd mod: = 57,104%
4th mod: = 28,247%
5th mod: = 10,599%
6th mod: = 2,999%