Remmina - The GTK+ Remote Desktop Client  v1.4.18
Remmina is a remote desktop client written in GTK+, aiming to be useful for system administrators and travellers, who need to work with lots of remote computers in front of either large monitors or tiny netbooks. Remmina supports multiple network protocols in an integrated and consistent user interface. Currently RDP, VNC, NX, XDMCP and SSH are supported.
Remmina-ssh-wizzardy

When the SSH tunneling features are not enough, you can workaround it with other remmina functionalities, e.g. with the pre and post commands in the Behavior TAB, or the SSH proxy command for the SSH connections.

Socks proxy connection

In this example, before to connect to the remote server, we create a socks tunnel, that will be closed when the Remmina connection end

ssh config

Host foosock
User foo
Hostname foorealserver
ControlMaster auto
ControlPath ~/.ssh/cm_sockets/%r@%h:%p

remmina

precommand=/bin/ssh -fn -N -D 9090 foosock
postcommand=/bin/ssh -O exit foosock