What is the best remote access program

This might be in the wrong subject so let me know if i need to move it.

I need to know what are my options for remote control to connect to client computers and do some work on them.
I just dicovered Netmeeting but i am un-clear how this works. I don’t have a static ip, but i can go to whatismyip and give someone that as long as i have my linksys setup with DMZ.
Will that work? or what should i be doing?

Are there any other free and secure ways? Or cheap ways?

Webex PC Now was cheap at around $8 a month for one computer but it takes a lot of work on the end users computer to setup.