One of the greatest strengths of World of Warcraft is its awesome sense of progression. Players level up and gain better and better gear as they progress through the game. Some people live for the raiding content, constantly striving for gear upgrades and stat optimizations. However, my favorite aspect of WoW's progression was and still is training new abilities. Leveling my warlock back in The Burning Crusade, I was amazed by every flashy ability I learned. Upon training Hellfire at level 30, I ran to the front gate of Orgrimmar and proceeded to ask a well geared level 70 character to duel. Amused, the 70 accepted and prepared to watch my futile efforts. I immediately popped Hellfire and died within a few seconds, all while laughing maniacally.
"Wow, you suck," said the 70 and rode away on his epic mount.
My lack of skill aside, the fun I had discovering these new abilities is unsurpassed by any facet of the game. Be it the terrifying Thunderstorm, the dumbfounding Disengage, or the hair-raising Heroic Leap, there are many cool abilities out there. And while some of them may have little to no practical application, every time I use one of them, I always think "Man, that's cool!"
So what's your "Man, that's cool!" ability? Did you discover it leveling your first character, or did you see another character use one of those nifty abilities and become inspired to level that class?