3. Imaginative and Challenge achievements - I chalk these two up in the same category, because they tend to be the most popular types. Imaginative achievements are usually those which require you to do some sort of unusual action or behavior that you might not otherwise do . . . Half-Life 2: The Orange Box has a ton of these. Challenge achievements are pretty obvious, they ask you to do things that are considered particularly difficult, either being optional, or exceeding normal performance . . . this would be like killing the Dungeon Guardian, or fighting Plantera without getting hurt. These also include the occasional "failure" achievement, which I would relegate as a subset of the Imaginative type.
while the rest of your ideas are great I don't see the pull of having players kill the Dungeon Guardian its just incredibly tedious and doesn't display any extreme amount of skill. Killing plantera without getting hurt is a much harder achievement and is an actual testament of skill and is the kind of difficulty Id like to see as achievements not have a surplus of gravity potions and a piranha gun.