The following graphic, which outline as accurate as possible, the types of dimensions implemented by various minecraft dimension mods from 1.3 to 1.12
Unless there is an error:
1. WIP dimensions are not included.
2. Only sufficiently feature complete dimensions are included in the diagram construction (Also, Mist of Riov ,Divine RPG and AoA are not added since most of the blocks in those dimensions are purely decorative or strictly for crafting progression related items).
3. Dimensions that are based on planets or Earth (Galacticraft and any space themed mods) are not included in the graphic. Dimensions based on food or ores are also not included (Sorry Deep dark).
4. As a time axis has not been added, prehistoric dimensions are not included (otherwise, they would be clustered near the overworld)
5. Mods that added a dungeon dimensions are not included as I have no idea yet on how to put them on the graphic yet.
Analysis: From the graph, we can see we are currently lacking a water dimension. We also don't have a purely light themed dimension as Aether is a air+light mix.
List of dimension mods used. Top to bottom left to right. If no link it means it is a vanilla dimension (except for sky dimension, which no longer exist):