Looks aren't everything, and sometimes it is best to go with function over form. For anyone looking to maximize their potential, picking the best race for mage is of vital importance. Let's talk about the ups and downs of each race of the Alliance, and figure out the best ones for PvP and PvE.
Human is the first and probably most common choice for mage. For PvP, Every Man for Himself truly shines, along with the rogue and druid-busting Perception. Getting to equip two high-end PvE trinkets AND being better at catching stealthers? Humans are amazing for PvP.
For PvE, however, these abilities are less useful. Sure, they will occasionally allow you to break some form of CC and continue DPSing, but this is a situational ability and is easily overshadowed by other racials. So for PvE-centric players, I would skip Human as an option.
Next up is gnome. Gnome is another good choice for PvP thanks to Escape Artist and their passive 2% resistance to Arcane. And Expansive Mind, a 5% bonus to Intellect, is great for anyone rolling mage, be it for PvP or PvE. Gnome is a solid choice for an all-around player.
The final option on the Alliance side for mages is Draenei. Gift of the Naaru, a fairly-powerful HoT racial, is pretty handy for PvP and even has some use in PvE; not dying is great for improving your DPS. And even if you aren't in risk of dying, taking pressure off raid healers can be good for the raid as a whole.
Gift of the Naaru isn't the big thing on the Draenei racial list though. Heroic Presence, a 1% hit bonus to yourself and your party, is what makes them worth rolling. Missing spells can prove fatal in PvP and gimp DPS in PvE, so being capped is vital...and this talent means you can stat more offensive stats instead of stacking hit. Rounding out their racial list is a 2% shadow resistance, all together making Draenei another good choice for mage.
So all we've really concluded is that unless you are rolling a human for PvE, you probably will do alright. But what is the BEST race for mage? For PvP, human is easily the best. The only thing better than one powerful trinket is two, and human can equip two thanks to Every Man for Himself handling all your CC busting needs.
And for PvE? It kind of depends. If you are going to be running with other Draenei, then Heroic Presence is wasted, since it doesn't stack. And even then, the Intellect bonus from Gnome is hard to ignore. So I'd say in most cases, Gnome is going to pan out to be your best choice for PvE.
And that's all for Alliance mages! Hope you know which race is best suited for your purposes now, and that you don't have any lingering unanswered questions. Be sure to check out my guide to Horde races when that comes out, soon!