What's your favourite SFTP client?

I've been writing an SFTP server. It's not complete but it is good enough to start testing against a wider variety of clients.

So what other SFTP clients should I test against? I'm disinclined to pay money merely to test interoperability but don't mind looking at free-as-in-beer clients; obviously free software clients are better in that I can look inside and see why they're doing things. I've got Windows XP, OS X and Linux and home and can get access to several other UNIX platforms.

The list so far.

( More information )

As part of the process I've summarized information about SFTP protocol version differences here.

Wanna buy a used peerage?

At this rate Levy's defence isn't going to be “I'm just the fall guy” but “prejudicial media coverage”.