Addons

Addons

Hard Surface/Modelling

Grass

Trees/Plants

Asset Management

Asset Management (paid): Manage your assets/HDRI/scenes/materials with thumbnails [2.8]
Gaffer (paid): Manage your Lights/HDRI's [2.8]
Alchemy (paid): manage materials
Lightarchitect 2.0 (paid): 3D lightning assets [2.8]
iMeshh Asset Manager (free): manage bought iMesh and own materials [2.8]

Useful Tools

Lapineige's Tools (paid complete/ free separate)
Anaranth Toolset (free): many small things (like shortcut for camera renderborder...)
MACHIN3tools (free) [2.8]
Matalogue (free): List of materials ans other node setups in toolbar
Speedflow (paid): Shortcut for modifier [2.8]
MiraTools (free)

Small Tools

3DM Snow (free): Generate snow on surfaces
Keyboard Layout Editor for Blender (free): Import layouts from Keyboard Layout Editor
Cobweb generator (paid)
Water Level Combiner (paid)
Align Tool (paid): align objects [*2.8 suppport planned]
Easy Rope (paid): generate hanging rope/wire between points [*2.8 suppport planned]
GreebleFX (paid): Generate Greebles [2.8]
ATOM BOMB: Data Management (paid): clean blend file
Randomizer (paid): Randomize Location/Rotation/other settings for objects/groups
Book Wizard Covers Generators (paid): generate random book covers

Shader

Animation

Other things

BLAM/camera and projector calibration toolkit (free) --> Alternative FSpy [2.8]
IES Lighning (paid) --> function included in Blender 2.8
MassFX (paid): Create things like many fruits in bowl [*2.8 suppport planned]
Baketool (paid): Easier baking [2.8]
Mirage (paid): create terrrain/landscapes [2.8]
Flip Fluids (paid): Improved/more advanced water simulation [2.8]
Blender Sensei (paid): Changes/tweaks Blender interface with custom hotkeys/workspaces/tools [*2.8 suppport planned]
Node2code (paid): create your own addon from node setups [2.8]

Sculpting

Compositing

Rigging/Character

Render Engines

Plugins for third party program support

[2.8] 2.80 compatible version exists