Grand Prix Dallas is approaching next weekend, and with it a glimpse into the Modern format of today. With on the horizon, I'm going to discuss the Top 20 decks in Modern, focusing on what recent upgrades each deck got from Kaladesh as well as recent innovations involving older cards. If you're unsure what you should play in Modern, I would highly recommend one of the decks I rank #1 through #7 in this list as those are the decks I consider to be the Tier 1 decks right now.
Concealed Courtyard and Blooming Marsh are really the only additions to this archetype. The biggest obstacle this deck faces is having to fight through the Dredge hate in the format, including Rest in Peace and Grafdigger's Cage. If Dredge is not common in your metagame, this deck's stock rises considerably. As is, it's all the way down to #20 on the list. It can still kill out of nowhere off a single Collected Company and it can also win through graveyard hate simply by attacking. It's still the best toolbox deck in Modern.
Perhaps the most consistent pure combo deck that will kill you by the fourth turn, Ad Nauseam is the best non-creature based combo deck in Modern. It's a bit fragile, but once it goes off, there is no stopping it since it finds three copies of Pact of Negation every time when it draws its whole library. Phyrexian Unlife gives the deck built-in protection against Burn too. The only way to disrupt this deck is by stopping them from resolving Ad Nauseam, either through counters, discard, Meddling Mage effects, Lost Legacy effects, or through attacking their mana while pressuring their life total.
I guess Dovin Baan isn't quite good enough for Modern, but this is the deck for it if it is. Decks with countermagic keep a lot of the unfair combo decks in check such as Living End and Ad Nauseam. This is one of the best counterspell decks in Modern because it also has plenty of creature removal spells to compete with all the creature decks of the format. Timely Reinforcements main deck is a bit of a concession to the popularity of Burn, as is sideboard Leyline of Sanctity. The planeswalkers and Snapcaster Mages give it game against Jund, Abzan, and Jeskai attrition decks.
Collective Brutality and Spirebluff Canal are the two recent additions to this archetype. Collective Brutality is a nice tool against Burn, especially with Snapcaster Mage, but is also useful in nearly every matchup since literally every deck in the format has either small creatures to target or instant/sorceries to discard. It's the best graveyard-based "fair" deck of the format, but this means it's also going to face a considerable amount of splash hate from anti-Dredge cards. Delve and Snapcaster Mage hate Rest in Peace, but only Snapcaster Mage minds Grafdigger's Cage. So depending on which hate card is more prevalent, Delver can sometimes sidestep it.
Lantern is easily the least fun deck to play against in all of Modern. It establishes control of the game fairly early, locking down combat with Ensnaring Bridge and locking you out of quality draw steps with all its Codex Shredder effects, yet unlike the combo decks of the format, it doesn't actually kill you for 20 more turns. So you have to either concede prematurely or grind out your 1% chance of winning for the next agonizing 15 minutes. Blooming Marsh is a great addition to this deck since life points are precious and the deck functions great off three lands.
Spirebluff Canal is less of an upgrade in this deck than in Grixis Delver since Jeskai is much more interested in continuing to make land drops beyond the third. It's nevertheless good enough to make it in as a painless way to cast Lightning Bolt or suspend Ancestral Vision on the first turn. Ceremonious Rejection is a welcomed sideboard card in this style of deck since it works great with Snapcaster Mage and can counter key spells against Affinity, Tron, and Eldrazi decks. On the play it can also stop a first turn Grafdigger's Cage, which is otherwise annoying for this deck.
Hunting Wilds isn't a new card, but it's a rather recent innovation to this archetype, acting as a mini Scapeshift of sorts that can ramp the deck up to 7-8 lands to win with Scapeshift. Some still play Cultivate or Kodamo's Reach instead, but I like this one as it's a more powerful target for Bring to Light. Given that this deck needs a certain threshold of Mountains and also wants to go all the way up to 8 lands, Botanical Sanctum isn't really what this deck wants. Blessed Alliance, however, is an interesting addition, offering some additional creature protection and life gain. It's especially potent with Snapcaster Mage in a Burn-heavy field.
The old fish-people will likely always be a deck in Modern. It's consistent, gets around Blood Moon, disrupts opposing mana with Spreading Seas, goes both big and wide with its plethora of lords, and has plenty of disruptive capabilities, especially post-board. Ceremonious Rejection is the most recent addition to the sideboard as a nice bullet in a handful of matchups.
Likely the best white aggro strategy of the format right now, "Eldrazi Taxes" hasn't really gained much since Battle for Zendikar except metagame positioning. It's not really interested in Concealed Courtyard because it would rather have Caves of Koilos for the colorless mana, Shambling Vent for the attacker, and Godless Shrine as an untapped fourth land to cast Thought-Knot Seer on time. Blessed Alliance is cropping up all over the place as an efficient answer to Burn that can also give Bogle and other aggro decks problems. Rest in Peace works great with Wasteland Strangler in this deck.
The deck hasn't changed much since the printing of Kozilek's Return and the banning of Eye of Ugin (and its replacement with Sanctum of Ugin), but a few metagame innovations have been made. Fog is an efficient answer to Infect and can buy that critical turn to set up a board wipe with Ugin or Ulamog. Thought-Knot Seer and Thragtusk are ways to go lower when the opponent attacks your mana development.
This is one of the hottest decks in Modern right now and easily the deck that benefitted the most from Spirebluff Canal since it is pretty low-to-the-ground and just wants to race. Given that it wants to pay life with Gitaxian Probe, Mutagenic Growth, and Apostle's Blessing, saving life with Spirebluff Canal is enormous. This is basically the red version of Infect.
Blooming Marsh is a pretty big addition to this deck since it painlessly allows Noble Hierarch or Inquisition of Kozilek on the first turn. The days of paying five life to fetch Overgrown Tomb off Verdant Catacombs to cast Thoughtseize feel like a distant past compared to paying no life to cast Inquisition of Kozilek off Blooming Marsh. Given how much better exalted gets in this deck since the addition of Grim Flayer, I suspect the addition of Blooming Marsh makes Noble Hierarch a mainstay in Abzan.
Some Primeval Titan Valakut decks are straight Red-Green while others splash white for Nahiri, the Harbinger. I prefer the additional angle of attack that Nahiri provides. It also gives the deck a natural answer to artifacts and enchantments. Going ultimate to find Primeval Titan is basically the same as finding Emrakul, the Aeons Torn since either one will kill the opponent immediately, so that's why the deck doesn't run any other targets for it. Titan is always the best target.
Now we're getting into the class of decks where all seven can arguably be considered the best deck in Modern. Death's Shadow Aggro is one of the hardest decks to beat since it wins quickly and attacks for a ton of trample damage with its Temur Battle Rage combo. It does a lot of the work for you though if your plan is to win through damage. Faith's Shield is one of my favorite additions to this deck, an innovation I first saw from Sam Black at the WMCQ. It makes perfect sense since fateful hour is turned on whenever you need it and it can protect all your creatures from removal or your own face from a lethal burn spell.
The only reason this deck does not run Botanical Sanctum is because it wants enough fetch lands to find Dryad Arbor in post-board games when people bring in extra removal spells. Blossoming Defense, on the other hand, is a very welcomed addition to this deck. It's basically the final piece to the Infect pump spell puzzle. There is no longer a need for Groundswell. Now you basically have additional copies of Vines of Vastwood to grant hexproof to your creatures. If Infect wasn't frustrating enough to play against already, things just got worse!
Wild Nacatl is the reason this deck is not interested in Inspiring Vantage. It hasn't gained anything recently and has actually gotten a bit worse recently with the addition of the enemy cycle of fast lands. People are also packing a lot more Blessed Alliances. Still, the deck is the most consistent deck in Modern and sets the standard for caring about your own life total, keeping all sorts of cards in check, most notably Dark Confidant and Thoughtseize. Speaking of which…
Blood Moon Jund was popularized by Raphael Levy recently and is about equally prevalent as non- Blood Moon Jund, keeping the opponent guessing whether they need to play around it or not. Liliana, the Last Hope is a fairly recent addition to the deck, but the most recent is Chandra, Torch of Defiance. This version of Jund is a bit soft to Burn, but very strong against combo and other midrange strategies. Blood Moon means it's not interested in Blooming Marsh, but the versions that do not run Blood Moon would be interested in the card as long as they have a low to the ground mana curve.
Like Eldrazi Taxes, the need for colorless mana combined with the frequent need for an untapped fourth land is why this deck is not interested in Botanical Sanctum or any other fast land. It really hasn't gained anything new. It's simply the best Ancient Stirrings deck, which is arguably the most powerful Impulse effect in Modern. This deck might also be the best Noble Hierarch deck in Modern, depending on whether you rank it above or below Infect. I've played enough Green-White Hatebears to know just how powerful of a setup first turn Noble Hierarch can be in an aggressive deck.
There was talk of Toolcraft Exemplar making it into Affinity, perhaps alongside Tempered Steel, but that has yet to be seen. It least I have not yet seen it. It appears Affinity decks are becoming split between Galvanic Blast vs Thoughtcast and Etched Champion vs Master of Etherium. This version hedges by literally splitting both. I also just want to point out the awesomeness of the MTGO nick Toastmachine. Well-played, Toastmachine, well-played.
The biggest winning from Kaladesh has got to be Dredge, an already Tier 1 deck that gained a huge upgrade in the form of Cathartic Reunion. Several decks gained better mana with the fast lands or a few small upgrades or sideboard cards, but Cathartic Reunion is just the stone nuts for this already very powerful deck. You absolutely need to be packing hate for Dredge right now unless you know for certain that your metagame is devoid of it.
This list is not exhaustive of every deck in Modern that is capable of winning a tournament. Elves, Bogle, Kiki-Chord, Living End, Knightfall, Hatebears, Storm, White-Black Tokens, and even Bloom Titan could take it down. But if your goal is to give yourself the best chance to win and you don't have a specific deck in mind that you want to play, I would recommend picking one of the decks near the top of this list, particularly in the Top seven as that is where I would make the "Tier 1" cut.