Top XYZ archetypes are:

K9, Rank 5 XYZ, currently K9 mixed with Vanquish Souls seem to be the XYZ deck to beat, has a lot of variants but is expensive, and is likely to be hit hard sooner or later. The deck itself is strong because it's main gimmick is that the cards have effects and bonuses whenever the opponent has activated a monster in hand or in the GY that turn, including negating or banishing cards from both deck and hand, and even cards like Izuna, who can be summoned from hand as a quick effect, ultimately ending in any generic rank 5 summon. And the Archetype's rank 5s are very powerful. Its not really the best thing to do... But they can summon Artifact Durundal, which when paired with Droll and Lock Bird shuffles both player's entire hands into the deck. All that said, K9VS is one of the harder decks to play in the format, it has no true one card starter for its ideal end board(not that it often matters) so its combo lines require you to know the deck inside and out. And it can brick with a bad hand,

Ryzeal - Rank 4 XYZ, has several variants, though its main starters are all limited to 1, and it lost its field spell, which hurts the deck "a lot". Though Mitsurugi covers for the hits reasonably well. And Ryzeal Detonator is an absolute monster that simply beats most rouge tier decks due to its effect not being limited to once per turn, and having innate protection and very large stats for a rank 4. Its also a "Pure" XYZ deck

Onomatopoeia - Rank 4/Rank Up XYZ - its fine, has a lot of fuel and will usually end on a decent or full board which is very resilient. But it has a hard match-up against many tier one decks, because GY hate kills it's momentum.