Pretty much all 4 man content. I am always amazed at how many people don't play Deep Dungeon. I look forward to every iteration of it. Take my newer FC mates through it. Solo it. It's the hardest 4 man content in the game with some of the best rewards.

Treasure hunts. In stark contrast as far as difficulty, Treasure Hunt Maps are super easy but the rewards are equally amazing. You have a brief stint in the open world followed by a romp through more randomized goodness.

And I think that's what it boils down to. Random is definitely fun to me. Smaller groups are always nice. Can't beat these two pieces of content.