RazorSQL vote here too. It is not free, but it's not expensive ($70 for a perpetual license and 1 year of free upgrades).
If you use it for work, it will pay for itself quickly. I was jumping between MySQL GUI tools, SQL Server and Informix DBAccess, some of them through VMs because I use a Mac for development. Having a single tool to connect to any database out there is pretty nice. It is also highly customizable, and very reliable.