I doubt I'll get much opposition if I say Jace is (arguably) the best card in standard. Sure, the decks he goes in aren't just flat-out dominating (Although I personally do feel U/W Control is the actual best deck in the format right now), but they're still out in force and Jace is pretty much the main reason they're so good. It's also becoming more and more rare where WotC print Planeswalkers this cheap that just entirely dominate a game by themselves, the only other 'Walker in standard that can brag a similar feat is Domri, but he requires some serious building around. Jace is just so warping to a game that games with him feel entirely different to games without him.
Oh and I totally didn't post this so I could mention how last night at FNM I ulti'd Jace and cast my opponent's Armed / Dangerous (The Armed part) on my AEtherling and just swung for lethal with a 10/1 double striking unblockable creature.
So yeah, discuss the magnificence of the best Planeswalker in standard right now.