Hail the Power Cosmic!

Celestial for the Win
If the entire technological might of the Star Wars Universe (including both Death Stars) was gathered into a single place, able to be harnessed with a super-computer which could enhance and improve the targeting between every ship in the Star Wars Universe, they still couldn't defeat a single Celestial.

The Mightiest Gods on the Marvel Earth vs the Celestials?

These are the most powerful beings on Earth, with powers and abilities far greater than even the most incredible of superheroes. Surely there isn't anything capable of defeating them, right?
When the Celestials came to Earth, the Council of Gods learned they weren't even in the same league...

The Council of Godheads were spanked right out the gate, no contest. They were so outclassed, they were forced to sue for peace or be destroyed.

The Heart of the Universe and the Infinity Gauntlet
Two of the MacGuffins known for being able to alter the fundamental fabric of the Marvel Universe. Which one reigns supreme?

The-One-Above-All is not the same as Yahweh in the Marvel Universe

Yahweh is the ruler of the Abrahamic monotheistic religions on Marvel Earth-616. Any of the religions such as Judaism, the various sects of Christianity or Islam are effectively under the auspices of Yahweh or his other aspects.

The-One-Above-All is something else entirely.

Bor Burison, Architect of Asgard was the mightiest Asgardian of these three.

In the Marvel Universe, Bor was believed to be among the gods that created the universe. He and his wife, Bestla, had a son and called him Odin.

While Bor was out founding Asgard, destroying the monsters of the early Universe across the Nine Realms, Odin secretly coveted the throne of his father. When a time-travelling Loki catches Bor in a magical trap turning him into magical snow, Odin does nothing to save his father. He instead takes over the rule of Asgard.

Don’t forget your parting gift on the way out.

Oh, you were hoping for more…

Odin couldn’t beat Laufey, King of the Frost Giants (they declared peace). Varying posts online claim Odin has superhuman strength. Is this true? Is he stronger than Thor?

Odin has powers beyond his phenomenal physical strength. Using those powers he can make himself (temporarily) stronger than even the mighty Thor. Comparing gods is, however, much harder than it is comparing strength between Human weightlifters...

Thor is physically stronger, but even he would be loath to confront Odin in combat...

It's not that he can't consume stars, they are just not the kind of energy he needs to survive. Stars are low-octane fuel for one such as Galactus.

Galactus isn't consuming purely energy such as that produced by the incredible fusion reaction of stars, Galactus converts the potential life energy of a world. He is absorbing the future potential, the temporal energies, the creative energy of any species potentially produced by that planet. When he is done, that world's ability to sustain a civilization is no more.

The Immune Systems of the Marvel Universe

The Enigma force and the Phoenix force are two semi-sentient cosmic forces which are hosted by sentient beings. They are a form of immune system in the Marvel Universe which help balance events by imbuing hosts with superhuman potential. When the balance is restored, the power tends to moves on to another alien host. Some hosts are already superhuman others have no powers at all and are given abilities by the cosmic force. Associated heroes: Captain Universe and The Phoenix

In the past, Galactus has been outsmarted by the likes of Reed Richards and Doctor Doom. Even Beta Ray Bill managed to get the upper hand once. Just how smart should we consider him to be considering these defeats?

Galactus, once Galan of Taa, was a scientist who survived the end of the previous Universe. As the Universe engaged in the Big Crunch, Galan was contacted by the Universe and woven into the fabric of the aborning Universe. Since then he has traveled for billions of years, engaging and destroying civilizations to feed his constantly growing hunger. But to live Galactus must feed on the life force of living worlds. And he is not particular if people are still living there when he shows up for dinner.

How smart is Galactus? How do we even determine just how smart he could be?

The Hulk is often described as the "the strongest one there is" on the Marvel Earth.

Which begs the question, is he stronger than beings who don't live on Earth? Could he take on the likes of cosmic beings such as the mighty devourer of worlds, Galactus?

In most cases: Not on a bet...