Mjolnir, because I like Mighty Thor better. She is cooler and since she's wielding it in Thor: Love and Thunder, I'm choosing that. Plus it's a total classic, can pound through groups of enemies, looks cool, and summons awesome lightning powers.

Stormbreaker. Both organic and kick ass.

Storm breaker has the capacity to summon the Bifrost, which is basically a huge laser if you look at Loki freezing it open

Stormbreaker seems stronger so Stormbreaker

The worthiness enchantment gives Mjölnir more use for incapacitating an opponent

Stormbreaker

The storm breaker is an axe and I believe it’s more powerful than a hammer and I think Mjölnir is a hammer.

I would say stormbreaker, because axes are better in battle to K11L someone which would be useful to thor when fighting against the Black monsters (sybiotes?) Also it can chop offs thanos's head but with a hammer it would take longer to K11L thanos unless your kratos

Mjolnir

Both