[joeythibault]

I've used Basecamp, Trac and Bugzilla. All are easy to use (and we've had some very non-technical users on them). My favorite though was trac, very easy to use, easy to set roadmaps and milestones. The bonus with bugzilla is that its more flexible (we're managing several development initiatives simultaneously). Basecamp is inexpensive, but I didn't find it as useful in managing bugs and support tickets (it was very useful in managing a grant application process though).

http://www.bugzilla.org/ http://trac.edgewall.org/

Personally, I don't think that the mode matters as much as consistency in method. I've successfully managed support tickets for smaller projects on a series of google doc spreadsheets without any problems. It makes for easier sharing with the client as well.

Bugzilla might fit your needs best out of the three I know about. Good luck!

[jaddison]

It looks like you're approaching the question from a project/client point of view; I think the OP meant from a product/user point of view.

ie. user purchases your product, has problem/question, emails [e-mail] and the support ticketing system picks up the email, autoresponds, etc.

I think what you're talking about is a bit different... although please do correct me if I'm wrong.