The idea here is for us to at least use the knowledge we have so far and try to find what the best type of damage is to use in various high level encounters and situations we find ourselves in as we approach 200 and beyond. Please submit any information you have. Most of this info will be from personal experience and may vary.
As of right now this list is very incomplete since it has been a long time since I have done most of these raids.
Unique Encounters -- 18 hour spawns
Tarasque -- Chemical Damage or Melee whichever does more for you.
*Most of the other 18 hour spawns have such short life spans that it is rather difficult to say what damage type is the best, but input is more than welcome.
Unique Boss Encounters -- Activated Chain Spawns
Hollow Island
*On the whole I've found Chem to be the best here. You'll do min on most brutes and champs past the first few rounds however so you should use a damage type that your min is highest with.
Mercs
Ian -- Energy Damage
Pat -- Energy Damage
Ris -- Fire Damage
Nelly -- Chemical Damage
Peter -- Chemical Damage
Other Unique Boss Encounters
Agent Lamb -- Melee
Poly --
Ljotur --
The Pest --
OE/OI -- Melee
Notum soldier/trainee --
Fiery soldier/trainee -- Chemical Damage or Melee
Diamondine soldier/trainee --
The One --
General Kronillus --
General Vivyane --
General Nirtox --
Mantis Queen --
Supply Master Eel -- Melee
Supply Master Smug -- Melee
High Commander Fredrickson --
General Khaeler(sp?) Jr. --
Jack the Legchopper -- Fire Damage
General leveling encounters --
RK missions -- Fire Damage
Hecklers (up to and including 210) -- Chemical Damage
High Level Shadowlands Encounters --
Faction Bosses in Penumbra --
Faction Bosses in Inferno -- Seems to vary from person to person, but overall the consensus is: Fire Damage
Xark and Razor -- Fire Damage
Ice Golem -- Fire Damage
Pandemonium
*We've done next to nothing other than kill yard trash in here on RK2 so I'm relying on all you RK1 folks for info here
*** A note on most of the high level encounters-- The majority of these high end SL encounters you will only hit for min damage against and all that really matters damage wise is what type of damage you have more buffing for. So take all this information with a grain of salt.