I want to use the classical GNOME categories (Accessories, Education, Games, Office, Sound and Video) in the Dash menu instead of the current Media Apps | Internet Apps | More Apps
You could try taking a look at the Unity Bliss Lens, which puts applications into category folders in the dash.
Instructions for installation:
- Download the package from https://launchpad.net/unity-lens-bliss by clicking the green button on the right side of the page.
- Extract the package into your home folder.
Run the following in a terminal:
cd unity-lens-bliss-0.1.3 ./configure –prefix=/usr –sysconfdir=/etc make sudo make install
Log out and back in to see it in the Dash.
This doesn't change the dash itself, but it does present you with a categorized view of installed applications. You can access it directly by using super+a, or you can just open the dash and tap tab to switch to it -- or click the App lens icon at the bottom of the dash. Anyway, it'll look like this: