I looked at Mac Help Mate and I think it might have had a free version too. I downloaded the app and then deleted it because I discovered that it supports many other functions beyond remote control that could get a neophyte user in big trouble (since you have to leave this program available to the person your trying to support).

I have used so many different ones. It's a real challenge.

I find that Teamviewer is by far the most responsive.

I used to use logmein, but sometimes it fails to start.
And VNC has trouble if you don't know how to port forward properly.

I was wondering peoples opinions on the more secure connector options: Beyond the Remote Control Software (some of which include their own). I did get Apple Remote Desktop. Tried it locally works nicely.

Connector's
Skype
Share Tool
Mobile Me

While not freeware, RHUB's TurboMeeting is a full-featured remote support and web conferencing tool. RHUB has no monthly fees, but you do have to pay for the appliance. TurboMeeting is considered as good as WebEx and GoToMeeting according to this review:

I can add TeamViewer to the list. I'll vouch for it, it works as well as most of the others on the list except maybe Timbuktu and Apple Remote Desktop.