In terms of popularity, the Borderless Surge Foil is shoulders above the rest, but the Normal print is also exceedingly popular right now according to TCGPlayer, and still one of the top 20 cards players have been chasing since the new set released
It is fairly common for your opponent to have a sizable battlefield presence with large blockers, and you just attack with all your disposable creatures and then use Conflagrate to finish the blockers off after damage
That said, integrating Planechase mechanics into the deck is a superb fit thematically
These will be full art, gold foil variants often of the most powerful Pokemon in the set
The mana cost is rather cheap, letting you get it onto the battlefield and take advantage of its effect very quickly
Collectors are also after legendary cards, for obvious reasons