PuTTY Connection Manager
PuTTY Connection Manager was mentioned in the 12 PuTTY add-ons. One of the major missing features in PuTTY is the ability to display multiple sessions in Tabs Which is well done by PuTTY Connection Manager.
Reference

SuperPuTTY
SuperPutty is a Windows application used primarily as a window manager for the PuTTY SSH Client. It allows you to embed PuTTY terminal instances inside of a windows form providing a better tabbed interface when multiple connections are used. Additionally SuperPutty has support for using pscp.exe to transfer files to and from a remote host. Local terminal sessions can be started with MinTTY.

SuperPutty does not do any ssh or terminal management itself since PuTTY does an excellent job of this.

MobaXterm
MobaXterm is your ultimate toolbox for remote computing. In a single Windows application, it provides loads of functions that are tailored for programmers, webmasters, IT administrators and pretty much all users who need to handle their remote jobs in a more simple fashion.

MobaXterm provides all the important remote network tools (SSH, X11, RDP, VNC, FTP, MOSH, …) and Unix commands (bash, ls, cat, sed, grep, awk, rsync, …) to Windows desktop, in a single portable exe file which works out of the box.

mRemoteNG
mRemoteNG is a fork of mRemote: an open source, tabbed, multi-protocol, remote connections manager. mRemoteNG adds bug fixes and new features to mRemote. It allows you to view all of your remote connections in a simple yet powerful tabbed interface. mRemoteNG supports the following protocols:

• RDP (Remote Desktop/Terminal Server)
• VNC (Virtual Network Computing)
• ICA (Citrix Independent Computing Architecture)
• SSH (Secure Shell)
• Telnet (TELecommunication NETwork)
• HTTP/HTTPS (Hypertext Transfer Protocol)
• rlogin
• Raw Socket Connections