thor is an asgardian.....they just age slowly.....galactus is a fundamental part of the universe but he to can be killed if he dosent feed for a while ad is very weak...and wolverine's healing facotr retards his aging....so he will probably live another few hundred years...but at the end he will die...also there is the concept of immortals that if not bothered cant die like olympians...but can die with sufficient force...or immortals that cant die either way like thanos becasue not only thats a part of his physiology but also becasue death wont accept him.
The Elders are also long-lived, not true immortals, as Thanos stated - he added a billion years to the Runner and turned out extremely wrinkled and old. Wolverine could probably live to about 500 if no one tried to kill him.
it has been stated that if an elder is occupied with the thing he loves like the runner with runnig they will not die...+grandmaster tricked death....so that no elder will ever die...so now they are truly immortal
Blazing Skull, supposedly. A man who's been beheaded and came back five minutes later is about as immortal as they come.
Blue Diamond since he's been transformed into a sentient humanoid diamond.
Aarkus, the original Vision.
I'm not sure if the Eternals are truly eternal or extremely long lived. The Titan Eternals are just extremely long lived, the Earth Eternals are more powerful, and may truly be immortal, if nothing disperses their molecules. A few of the Deviants display Eternal like aspects, Ghaur, for one.
Ulysses Bloodstone, when in possession of the Bloodstone. Upon losing it, he died. He had been alive, and had not aged since pre-recorded history.
I believe Dracula is. He can be killed by a few means, but has yet to be permanently disposed of.
Controllers
Zamarons
Guardians
Olympians
Asgardians
Jin-En-Mok
Other pantheonic gods
Angels/Archangels/Fallen Angels
Lilim
Triarch
Hyperman
Superman Prime
Endless
Great Beast
Yahweh
Prescence
the Word
the Voice
TOAA
LT
Galactus
Heralds
Parallax
Sentry
DC1000000 charachters
5th dimentional imps
Creatures from dimentions 6-10
Celestials
Titans
Eternals
Titans of Myth
Eldars
Solaris
Phoenix
Watchers
Order
Chaos
Other abstracts
New Guardians