GNOME Shell with these extensions: https://extensions.gnome.org/extension/578/slingshot-app-launcher/ https://extensions.gnome.org/extension/156/quit-button/
Then install the docky package (sudo apt-get install docky) and start it up. That seems to be pretty close to ElementaryOS, though this is only based on a screenshot of ElementaryOS (I've never actually used it).
