Filezilla is a powerful GUI-based sftp client.
apt-get update apt-get install filezilla
LFTP is a simple and powerful text based ftp client which supports FTP, SFTP, HTTP and HTTPS.
The LFTP package in Debian is called lftp and is installed with
apt-get update apt-get install lftp
rsync -av --delete /here/ user@host:/there/ rsync -av --delete user@host:/there/ /here/
SSH comes with scp/sftp.
midnight commander (mc can browse remote folders over SSH. See menu > Shell Link)
Wget is a simple and powerful command line download tool which can be used to retrieve web pages, whole websites and files from FTP servers.
The Wget package in Debian is called wget and is installed with
apt-get update apt-get install wget