Anger of the Gods for affinity, zoo, and any other aggro deck. Exiling is relevant against abzan coco.
Crumble to Dust obligatory hate for tron and our new overlords, eldrazi.
Flashfreeze
hard counter that comes in vs almost any deck running red or green, or both. Seems limited but it has more targets than Dispel or Spell Snare in these matchups and that's where I want extra counters.
Engineered Explosives my second cheap wipe of choice. Great against aggro and really puts a beating on merfolk, set to 2 to kill most lords and Spreading Seas, has a similar affect on hexproof auras.
Izzet Staticaster
Mostly useful against tokens, like in Lingering Souls decks, eldrazi scions, and any other deck that has x/1 creatures.
Keranos, God of Storms my grindy finisher of choice. Really hard for control decks to deal with, outside of Crytpic command and almost impossible for jund and abzan to deal with.
Languish a little extra stopping power, comes in against aggro and midrange.
Molten Rain More obligatory tron hate, comes in against greedy mana decks like jeskai control, jund, abzan, etc. Preferred to Fulminator Mage because it's easier to recur. Currently wondering if Spreading Seas could be better, as it's cheaper and cantrips.
Olivia Voldaren great in midrange where she can take over, and some players like her in matchups like naya zoo. Considering Bitterblossom in this slot, not for the midrange matchups as much (Abrupt Decay), but for control matchups.
Spell Snare Counters a very large amount of spells that we care about in a large variety of matchups.
Vampiric Link our burn hate. Put it on Eidolon of the Great Revel and laugh. Or put on angler or another beater for a nice lifelinker.
Vandalblast My affinity hate card of choice. Easier on the mana than
Shatterstorm
or Shattering Spree. Kolaghan's Command helps me get there to overload.