Best for a WOW power leveling build

In WOW these represent our best recommendations for a WOW power leveling build:

Level 15 – Juggernaut – This will reduce your charge cooldown to 12 seconds instead of 20 seconds. This will help you kill things even faster. 
Level 30 – Impending Victory – This thing is pure gold for any spec. It's a decent attack that doesn't increase your aggro that much. In addition it does a small heal at the same time and has a very short cooldown. Decent attack, minimal aggro, healing and a short cooldown? What's not to love.
Level 45 – Disrupting Shout – Not all that powerful while you're leveling but this area interrupt spell is perfect when fighting a group of casters. Cast this and you will disrupt them and silence them. A great thing to use to protect your group.
Level 60 – Dragon Roar – Another great group fighting spell. Instant cast and damages everything close by as well as knock them down.
Level 75 – Mass Spell Reflection – Give everyone in your party spell reflection. The next spell cast on them is reflected back on the caster. This can be very annoying when you are running battlegrounds.
Level 90 – Avatar – A great way to free yourself from all roots and snares. It transforms you into a bigger, badder version of yourself and ups your damage output by 20%.