I'm a big fan of DBVisualizer (http://www.dbvis.com/), and have used it almost daily for ~6 years now on OSX. It's not a perfect OSX app (it's cross platform Java, but quite good looking for what that normally implies). Lots of power, doesn't crash, decent looking, and it works for pretty much every relational database out there (including MySQL, PostgreSQL, and Oracle).

I own a SequelPro license (as well as licenses for a couple of other non-free tools, RazorSQL and Querious) and I always come back to DBVisualizer.