A recent project using a remote database server forced me to go looking for a suitable database client for my Mac. Previously i had used EMMA on Linux, but as I only has my macbook to hand I decided to have a look into what was available.
A quick google turned up Sequel Pro - an open source project - http://www.sequelpro.com/
Sequel Pro is a very capable tool, that works flawlessly, it supports SSL connections and had a wide range of encoding options. The layout is instantly familiar to anyone who is used to using phpMyAdmin, and the interface is pretty intuitive to use.
The query editor allows easy query management with both a history feature as well as a favourites menu to keep track of your more frequently used querys, this alone is a great feature for anyone who needs to use the same querys over and over. The query editor also provides basic text editor functionality and syntax highlighting to make life a littel easier, it also includes auto complete.
Overall, if you need a remote database client, or simply want to use something other than phpMyAdmin, I would reccomend Sequel Pro. A great application, at a great price.