Pioneer DJM-2000

 
It's designed to sit flush alongside the CDJ-2000s, and Pioneer has mirrored the same slanted-front design. When you're in front of four CDJ-2000s and this mixer, it not only looks awesome, but the amount of flexibility in how you choose to DJ is immense with this particular setup.
Although the mixer can work splendidly with any other CDJs, its integration with the 2000 series is incredible.

"Using start/stop and MIDI on/off, you can choose when to send MIDI from the mixer and when not to."

Around the back there are six LAN ports, with four ports to connect CDJ-2000s using the LINK technology and two for connecting two separate laptops running Rekordbox.
This means that laptops can be connected via a single LAN cable and, when using the CDJ-2000s, can act as a means of searching and browsing your music, while all the actual DJing is done on the Pioneer hardware by dragging songs directly onto the Live icons of the CDJs or even directly on to the mixer.

 

When songs are dragged onto the DJM-2000 mixer icon, they are previewed - you can use the Link Cue function to preview tracks without having to load them to a deck. This makes browsing your laptop-stored music even faster. Of course, as mentioned before, this is only one way to DJ using this mixer.
Inside the DJM-2000 there's also a 24-bit, 96kHz, eight-channel soundcard, so it's easy to hook up a laptop and use the DJM-2000 as a multi-output soundcard and mixer without any extra external boxes or audio interfaces required.