Cata was my favorite expansion on my Tauren Holy Priest. There was this thing called Chakras. I loved seeing that runic energy symbol flashing under my character and changing the color depending on single target healing/aoe/or damage. I wish the Chakra System survived after that expansion. Plus, both Holy and Disc had a lot of smart heals and instant cast spells that made things so easy and with all the gold sparkly spells, it was such a beautiful time to be alive! 