Depends on the user, but if I need something quick I use putty. First google result for "ssh client". If I need something not-so-quick, I pull out a Linux box.
yeah, putty for windows (theres a CE version too) and the standard SSH command for linux/bsd
i can't connect my XP virtual machine to my Debian VM... actually, i can't even get my Debian's IP address...
Putty is my default ssh client.
Make sure your Debian VM is running the ssh process to allow ssh connections. its 'sshd' of the top of my head.
have you got the VM set up for shared, virtual or actual networking