www.helpcenterlive.com & www.clickchatsold.com

The above stated chat systems which one do you guys think is the best or you have any others in mind care to share??

What kind of chat system do you want anyway?

If you are some kind of company (e.g. webhosting) and want to give "live support", then the best one is HelpCentreLive IMO

where as if you want a chat system for your website for members to chat among them selves, then you should try this chat script called "phpOpenChat", i think thats the best one IMO for website use