Linux/Unix ssh-The real deal!
Putty-SSH Terminal Emulator for PC
NiftySSH-SSH Terminal Emulator for Mac
SecureCRT-Win32 Terminal Emulator Capable of SSH ($99)
MindTerm-100% Java SSH Terminal Emulator ($Free!)
If you choose to use MindTerm be aware that the documents are translated from Swedish, and it shows. To execute the MindTerm Java applet from Windows 98/NT/2K use this command:
jview /cp:p mindtermfull.jar mindbright.application.MindTerm