ConEmu is a Windows console emulator which aims to make working at the Windows command line a far more comfortable experience.
The program's tabbed interface makes it easy to run and switch between multiple sessions, for instance. And these are extremely configurable. You get to choose the shell (cmd.exe by default, but it can be whatever you want - even a simple GUI app, like Notepad), the startup folder, whether it's launched as an administrator, and more.
Each individual console has many simple advantages. Resize a window and your command line output will scroll accordingly, for instance; an "always on top" option keeps the console on top of other windows for easier access; and Caps, Num and Scroll Lock icons highlight the status of each key (and can be used to change it, so for instance clicking "Caps" will toggle your Caps Lock status).
Handy integration with Windows 7/ 8 sees you able to create custom Jump List tasks from within ConEmu, allowing you to launch them directly from your taskbar. While the program can detect the progress of many operations - chkdsk, say - and will display an indication of this both in the window title, and on the taskbar (the Wiki explains more).
And there's just so much more here. There's enormous control over the fonts you can use in a console, for instance. You can have your own custom background image. There's a lengthy list of keyboard macros, as well as the option to create your own. And you can control window transparency, colours, Explorer integration, and the list goes on and on. (No, really: you could make an excellent console emulator just with the features we haven't mentioned.)
All this power doesn't get in your way, though. If you prefer the simple life then you can ignore most of the complexities and still see immediate benefits from ConEmu. Only if you start delving into the menu and settings dialog does sheer volume of features become apparent.
ConEmu is one of the most powerful and comprehensive console emulators around, so packed with functionality that it could take a very long time to fully understand everything it can do