Ask HN: I need bug reporting/feedback for my web app. Suggestions?

I'm about to launch a SaaS application and need a bug tracker. The basic requirement is pretty simple: allow users to raise bugs and submit feedback easily from within the app or via email. Easy tracking and workflow processing and possibly some sort of user forum.

In addition - and this is where my research has come a cropper - I'd really like users to have the option of filing a screenshot to their bug report by simply checking a box or clicking a button. Does anything like this exist? If not, what are you thoughts on the existing players (Zendesk, Uservoice, Kampyle, Tender etc) and what they're like to use on a day-to-day basis?