Sequel Pro: I've been using this a bit and so far so good. It supports multiple open connections, but only one SQL editor per connection. You can open a SQL file into the editor but then it doesn't clearly display what file you have open which is annoying. Otherwise it seems solid. MySQL workbench: MySQL workbench (for architecting) and Navicat for MySQL (for storing & scheduling common queries and report generation) are both great with enough differences to warrant mentioning both.