Hearthpwn

I strongly disagree with the placement of Twilight Drake in mage (S class). The current arena meta is quick, tempo/zerg based. Twilight drake is a card that benefits the most in control decks; if you have a play each turn (excluding turn 1) it will come up to be at most a 4-4/4-5. Bomb Lobber and Sunwalker are in general far superior arena picks for mage (the 4 spots for mage is over saturated with cards such as Fireball, Piloted Shredder and Chillwind Yeti, they rarely need other picks). In my opinion flamewalker should also be A rating. There aren't many great 3 drops for mage other than the secrets and mechs, and a reliable mage deck always has a couple spells. 

Grim Patron should not be an B rank across the board. It is fair only in classes that can abuse it (aka mage, warrior and paladins) and even in those cases it requires additional mana making it a super-late game combo card; it is a D-F rate card for druids,  rogue, shamans, warlocks and hunters; the trigger is extremely unlikely to go off late-game and without a way of triggering it a 3/3 for 5 mana is just game killing. In arena i would never pick this card over Sludge Belcher. 

Quote from Erxos4 »

The GvG tier list is really off if you ask me, though that's not surprising with how long it's been out.

Legendary:

• Gahz'rilla A -> B tier. I'm hesitant on this one... but I don't like marking this as A tier, in the end it requires some setup before it gets scary and does nothing when you put it down.
• Sneed's Old Shredder A -> S tier. It may be a bit hard to get off, and could get silenced, but if it doesn't it can win games on its own.
• Foe Reaper 4000 A -> B tier. It's alright, but it suffers from the same issue as Gahz'Rilla, it costs 8 mana and doesn't do anything unless it gets to attack.
• Toshley B -> A tier. It's possibly the most consistent Legendary in the game.
• Mogor the Ogre C -> B tier. Not sure about this one, but it has alright stats and you can trade first then put down Mogor, which means you're not suffering from it as much.
• Flame Leviathan C -> B tier. Not sure about this one, but it seems better than it looks.
• Blingtron 3000 D -> F tier. Some people have said it's actually decent but I'm not buying it, yet... It's a 5 mana cost card with bad stats and a symmetrical effect that can randomly screw you over. Doesn't sound great to me.
• Mimiron's Head D -> F tier. Way too much setup required for arena, and its stats are subpar if the effect doesn't go off.

Epic:

• Piloted Sky Golem: A -> S tier. Superb card, not much to be said.
• Quartermaster B -> A tier. If not S tier. The buff is crazy strong.
• Shadowbomber C -> F tier. Priest doesn't do rush downs, period.
• Wee Spellstopper C -> B tier. It has some crazy synergy with cards that need protection.
• Enhance-o-mechano D -> B tier. It's like Bloodlust in terms of its win-more power except doesn't require as much setup.
• Sabotage B -> A tier. It's really not that hard to just make this a 4 mana Assassinate. For that matter I think Assassinate should be A tier, not S tier, but whatever.

Rare:

• Muster for Battle A -> S tier, if only for the Quartermaster combo right now. If you get it you pretty much win the game unless you get hit by a Flamestrike. Even without, it's not bad and you have other buffing options.
• Siege Engine A -> B tier. Fact is that it's a 5/5 for 5 with a lackluster special effect as he's too squishy and slow.
• Arcane Nullifier X-21 B -> A tier. It's a superb blocker.
• Bomb Lobber B -> A tier, if not S tier. This is like a Stormpike Commando on steroids most of the time. Speaking about 5 mana cost rares, what the hell is Sludge Belcher doing in B tier? He's easily S tier.
• Madder Bomber B -> C tier. I've rarely had good RNG with this guy and due to the huge range of what could happen it's practically impossible to play him unless your side of the board is empty.
• Upgraded Repair Bot B -> A tier. The effect is really not that hard to make use of, and even without the stats aren't too bad.
• Powermace B -> A tier. Again, the effect is really not that hard to make use of. I had a 12 wins Shaman draft where multiple times I won the game by getting that buff off on the 3/2 Windfury minion or even just a Harvest Golem.
• Kezan Mystic C -> A tier. If you manage to steal a secret it's absolutely huge. Against a Mage it practically wins you the game. If only it were a 4/4 then it'd be S tier easily, and even without I'd possibly pick it over some other S tier rares for its ability to win games against 1/3rd of the classes on its own (2 of them being extremely popular).
• Recycle C -> B tier, if not A tier. The reason is simple, it's the only hard removal a Druid has at it's disposal. No, Naturalize doesn't exist, don't be silly. On top of that the opponent having to redraw the card is pretty big.
• Call Pet C -> D tier. There's really not enough consistency on getting beasts anymore, you'll simply not get much out of it most of the time.
• Goblin Sapper C -> D tier. The effect really rarely ever comes into play and a 3 mana cost 2/4 is rather lackluster, especially compared to the other things in C tier.
• Fel Cannon D -> C tier. It's really not hard to get value out of this card, the fact that it can hit your own minions can usually be worked around.

Common:

• Darkbomb A -> S tier. I think that with the Soulfire nerf, Soulfire should be lowered to A tier also. Darkbomb is pretty much the replacement.
• Anodized Robo Cub A -> B tier. It's a really good card, but I just don't feel it competes with things like Shrinkmeister, Whirling Zap-o-matic and Shielded Minibot. Perhaps the former actually deserve S tier, but I'm hesitant to label 2-drops S tier... Similarly, I'd pick them over Burly Rockjaw Trogg, but it's not right to say Burly Rockjaw Trogg should be B tier. I dunno, this one is awkward, this pick really requires context on what your deck needs.
• Ogre Brute B -> C tier. Fuck this card, I hate the RNG on these Ogres and if they come without special effect I'd rather just not have them. They can lose you games with their shenanigans.
• Tinkertown Technician B -> A tier. The effect isn't that hard to get off, and you're putting down a 4/4 for 3 AND getting a spare part? Honestly if I had a guarantee for my deck to contain at least 5 or more mechs I'd rate this S tier.
• Snowchugger B -> A tier. The effect is certainly better than Ship's Cannon and Stonesplinter Trogg, I don't see why it's in the same category as them.
• Floating Watcher B -> A tier. Arguably S tier, this card can win games on its own, but the little setup requires and that it's usually actually a 7-drop makes me hesitant to outright call it S tier.
• Goblin Auto-Barber B -> A tier. Honestly I'd almost rate this S tier. It has easily the best battlecry of any 3/2 2-drop, but again I kinda don't like any 2-drop being S tier.
• Velen's Chosen B -> S tier. Really? What is this card doing here. This card is in dire need of nerfing. If there was an SS tier, this card would be sitting there, alone, on the throne, laughing down upon all other cards.
• Ogre Warmaul C -> F tier. This card is garbage. The RNG is worthless and Warriors already have enough weapons. I've gotten 3 Warrior drafts since GvG, in all cases I had more than enough weapons and Ogre Warmaul, if I had drafted it, would just sit in my hand going "Hey! I'm a worse Death's Bite that will randomly screw you over!". Yeah, no thanks.
• Tinker's Sharpsword Oil C -> B tier. Not sure on this one, it requires quite a bit of setup but the amount of damage this card can help you pump out is insane.
• Warbot D -> F tier. Trash card. Barely ever gets to enrage, and even if it does it's completely insignificant.
• Annoy-o-Tron D -> A tier. This card is amazing, I have no clue why you rated this D tier. In terms of turtling power it's practically a Sunwalker, for 2 mana!
• Antique Healbot D -> C tier. For some classes this'll be even higher, but the healing amount is so high that I'd say it's C rank for any class bar Priest at the least.

Nice request! i agree almost entirely. 

The main cards i don't agree with are Dark Bomb, Ogre Brute, Annoy-o-Tron, Wee Spellstopper

i am unsure also about Antique Healbot, as i personally rank it below average. 

Dark Bomb although a great card (fully deserved at least the A spot) is not a game changing card, and warlock in arena is almost entirely about zerging the board and waiting for your turn 5-6 power house before closing up the game.  If you compare it with the other common S-tier cards for warlock you'll notice that those cards have the potential of 2-1 anything of their mana cost and lower (and can sometimes trade upward). Dark Bomb does not have that potential. Although it is a good card, it is not a MUST pick for warlock (i personally still prefer Soulfire as the extra 1 damage is absolutely worth a card. 

Ogre Brute: i understand you might have bad RNG but that does not make the card bad.  A 4/4 turn 3 has an absurde presence on the board! sure it might lose you games against super-aggro decks that just ignore it and go face but against slower decks (which are most likely what you'll encounter at higher wins) i'd like to argue that this card is insane. There are times when i actually happily pick this card over some S and A tiers. 

Annoy-o-Tron: I'd like to argue that is card is actually sub-par. and deserves at most a C rank. Sure if you play this card on turn 2 and the opponent has an empty board and you have an hero power that can deal damage to minions than the card is alright (it is still not great). In arena early board presence is usually what decides which deck will win, and this card is reliant on using your hero power to trade upward, which can result in placing yourself behind the enemy. It is alright in aggro oriented decks where you do not care about card value, but other then that, this card is inferior to Sunwalker on all aspects.

Wee Spellstopper: I'd like to disagree with placing this card in a higher tier. A 2-5 on turn 4 is just underwelming and may as well cost you the board. Yes it is true that this card goes well with Water Elemental and otherbig threats, but chances are you will not play them on the same turn, and if the opponent does not have an answer right away, chances as he will not have one the turn to come either. 

Other then that i agree with your propositions almost entirely!

Nice Job!

A card i would like to argue does not belong in the B tier (but C instead) is Clockwork Gnome. The card is just slightly better then leper gnome in arena due to its mech-synergy and because it gives a spare part, but that by itself is not good enough to place it along with cards that actually affect the board. Take Mechwarper and Micromachine; the synergy provided by this cards is infinitely  better then that provided by mechwarper. Micromachine can at times be a win condition by itself if not dealt with readily. Mechwarper can just allow you to out pace your opponent really quickly. It is just not fair to place clockwork gnome in the same category as Mechwarper and micromachine