The best native VNC solution I have found so far for Mac OS X is Chicken of the VNC over at Sourceforge. It currently stands at version 2.0b4 that dates back to 2006 and was released under the GNU GPL.
“Chicken of the VNC is a VNC client for Mac OS X. A VNC client allows one to display and interact with a remote computer screen. In other words, you can use Chicken of the VNC to interact with a remote computer as though it’s right next to you.“