PuTTY - Popular free terminal application. Mostly used as an SSH client.
Remmina - 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.
MobaXterm - Enhanced terminal for Windows with X11 server, tabbed SSH client, network tools and much more
rdesktop - rdesktop is a free and open source remote desktop protocol client designed to make the users able to manage their PCs in a new way.
iTerm2 - A terminal emulator for macOS that does amazing things.
KRDC - KRDC is the KDE Remote Desktop Client.