For people who are new to the genre, Essential Mixes are one of the best ways to get to really know EDM artists. While artists typically get popular through hit singles, in full sets artists make a lot of experimental tweaks and changes to make it a unique experience. In the same way that CD's killed the full-album experience, live sets are bringing that "full" artist experience back.
I've compiled a short list of well respected DJs in case you want to use this site to explore other big names in this type of music beyond the usual suspects (Deadmau5.) There are many, many more and this is just a sampling of different sounds from the most recent mixes only.
Above & Beyond, Kaskade, Nero, Cosmic Gate, Flux Pavilion (dubstep), Jamie XX