There are quite a few different VNC clients available for Mac, and most of them are, in my experience, pretty disappointing. And totally unnecessary, because OS X actually comes with a build in VNC viewing client which works fine. For some reason though, Apple have kept it pretty well hidden.
Never fear though, because once you know the location, it’s easy to find and use.
It’s pretty simple, but then I’ve never found the need for all the extra crap a lot of the viewing clients come with – I just want to be able to control a remote computer!