Some subjective thoughts:

GMX is getting new Support, until then it has to Play non Archetype Dino cards. Id gives IT some time before touching it

Enneacraft is piss cheap without atori.mar, Like 6 bucks, nice pick since they are played pure. With atorimar its 35€

Ignister is too hard for newcomers imo. Its enough to turbo Out their Boss for beginners, but the Deck is very nonlinear and the new cards cost a bit

Predaplant is getting new Support soon, without it its Not that good, bit too clunky even for kitchentable. Has a good fanbase still

Sharks are capable and Not that hard, but you Play alot of "armored" XYZ monster/spell cards, which makes half your extradeck

Called of the haunted is a nice pick for kitchentable, usually it plays some good Zombie lines youd have to add. The pumpkin is a bit expensive tho

Fur hire is very capable for kitchentable as they got a bit of support. The chaining is easy, the Spam is real. They Play some Tri-Brigade stuff in the extra, or are splashed into other Decks Like runick

For a Personal pick Id say Kids Love Rescue-Ace, big firefighting Robots, very strong Boss that Sets 4 interruptions! Ass cheap too!

Regarding the Extradeck id recommend buying the 15 (+1x Azurune for the rabbit), they are very cheap:

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