[thelist] looking for ticket system recommendations

[Sarah Adams]

I'm looking for a ticket system to use for client requests and support 
tickets. I've searched google and came up with some possibilities, but I 
can't tell whether they're any good from looking at their sites. So I'm 
soliciting recommendations based on your experiences with ticket systems 
you've used.

Required features:

- very easy (for my client) to use
- ability to prioritize tickets, not just with a few levels, but 
actually sorting the entire list of tickets into the exact order I want
- ability to categorize tickets
- low or no cost

Nice-to-have feature:

- a field to indicate a time estimate for completing a request

-- 
sarah adams
web developer & programmer
portfolio: http://sarah.designshift.com
blog: http://hardedge.ca