The number one on the list is Hammer. The deck originated as a mono white deck. It was already surprising as white had been thought to be the worst colour in all of Modern. Yet, all the deck needed was contained within this one colour. However, after some time players started adapting a seemingly free black splash to utilize cards such as Thoughtseize.
In a nutshell, the deck is a mix between Affinity, Boggles, and Infect. Its strength lies in the fact that it can present literal turn 2 or turn 3 kills. Not a lot of decks are equipped with the proper tools to combat such fast nut draws. If it was just a fast-kill deck, then it would not be able to thrive in such an interactive meta as it does. The truth is that the deck is supremely resilient and has very strong late-game.
The very first reason is Lurrus of the Dream-Den. As most people already know, having a companion is superior to not having one, but Lurrus especially enables easy rebuild – you can replay either the destroyed enablers or pay-offs. On top of the companion, there is Urza’s Saga. Not only do you get 2 huge Construct tokens from one, but also cheat a Colossus Hammer immediately into play, which is especially relevant against countermagic and effects such as Chalice of the Void. A non-zero number of times you’ll have the Saga/Lurrus Draw and just outgrind most opponents just on the back of those two.
The key here is that the opponent has to be constantly wary of a potential kill out of nowhere. It gains a lot of so-called false tempo thanks to that – opponent is playing around something that might or might not be there. Some people even experiment with non-Lurrus builds, leaning more on Stoneforge Mystic tutor targets.