MySQL Workbench is the official MySQL client from Oracle.
Installation from file
Download the latest package from the official website: http://www.mysql.com/products/workbench/
Download the .msi and perform a standard installation
Download the '.deb and install it:
dpkg -i mysql-workbench-community-6.1.7-1ubu1404-amd64.deb
Installation from repositories (Linux)
You can perform a standard apt-get installation using:
apt-get install mysql-workbench
Note that the repository version is not the latest version available, but the latest stable release that went through the Linux's validation protocol.