Hearthpwn

Flamewaker, such an annoying card that can get out of control really fast if you don't kill it.

Discount: Sorcerer’s Apprentice, Radiant Elemental - in Wild Emperor Thaurissan

Value “generators”: Lich King, Ysera, Lyra the Sunshard

”Cycle”: Nothshire Cleric, Acolyte of Pain, Mana Tide Totem, Stargazer Luna, Gadgetzan Auctioneer

Possibly snowballing: Lightwarden, Mana Wrym, Murloc Tidecaller, Vicious Fledgling, Hench-Clan Thug, Knife Juggler, Frothing  Berserker, Tundra Rhino, Spiritsinger Umbra, Dragonhatcher, Violet Teacher- in Wild Shade of Naxxramas

Order matters: Sonya Shadowdancer, Scavenging Hyena, Flametongue Totem - in Wild Kel’Thuzad

Everything that gives spell power to my opponet has to die.

Just OP: Archmage Antonidas, Malygos, Prophet Velen, Doomguards - in Wild Brann Bronzebeard, Fandral Staghelm, Sylvanas Windrunner

Also, I don’t hate any of the cards mentioned, it just seems unfair to lose to those cards just because you don’t have always in hand/on board a way to answer ASAP which would be ideal.

Cards that generate value each turn: Ysera, The Lich King, Cobalt Scalebane etc.
Cards that snowball if unchecked: Scavenging Hyena, Hench-Clan Thug, Vicious Fledgling
Cards with strong ongoing power: Archmage Antonidas, Prophet Velen, Lyra the Sunshard, etc.

Emperor Thaurissan

Brann Bronzebeard

Snowflipper Penguin

Flamewaker although the card has decreased in powerlevel, compared to other Wild synergies. 

Yet on my top hatelist.

Lyra, houndmaster shaw, all end of turn cards like lich king, any card cards that give all minions something. Ie tundra rhino

Well I can't attack and kill Frost Lich Jaina so I just commit suicide... concede...

In arena, Green Jelly can be a surprising threat

In addition to what has been mentioned: anything with Poison or Windfury, Jaina's Water Elementals (freeze you when they attack), anything that can be Shadowstepped by Rogue for more value, Odd Paladin's silver-hand recruits, anything with +attack when damaged (Warrior), anything with high attack (giants, etc.), Spider Bomb, Despicable Dreadlord, Wild Pyromancer, Shadow Ascendant, Dragonhatcher.

I always have to kill Bolf Ramshield before killing my opponent.  Always.  Any other minion the are times where you can ignore them completely.  Not so with Bolf.

That gentleman is S Tier.

Back before Standard was a thing, Gahz'rilla and Kel'Thuzad