I recently upgraded my monitoring system to Genelec 8240 Smart Active Monitors, and wow am I happy that I did.
For people reading this that aren't familiar with studio loudspeakers, Genelec make some of the finest available, and they can be found in most top recording studios and audio post facilities around the world.
Recently they also introduced the SAM series (Smart Active Monitors), which have the ability to adjust the sound they reproduce depending on the room they are in. Very cool. Basically you pair them up with the GLM kit, which includes an interface and microphone. The speakers perform a filter sweep from low to high frequencies and the room's frequency response is captured by the microphone. The the speakers can then compensate for any room resonances or abnormalities so that what you are listening to is not coloured by the room you are in.
What all this means is that you are hearing a flat response - and that allows you to make good decisions when mixing. Ultimately the goal is for your mix to sound great in any room, under any circumstances, and these monitors help get that result.