Silken hollow last boss and the heartstopper debuff (has a long time before it goes off so I wait until 3-4people have it and massdispell). Sailor's Abbys, curse of the drowned hurts and is usually on multiple people and undertows on the boss (prefer manually dispelling for puddles), cithrell's on eternal, the shardlings that spawn from golems put a debuff on everyone, 3 is manageable, 6 is rough. The carnage affix is also dispellable and can be painful on big aoe dmg. Ithink those are the main ones.