OK, here's a serious list, reprinted are the entries from other posts for
"Re: Immortals wanted"

sun tzu(sp)
bhoddidharma (he who attained nirvana at the henan shaolin temple
  and credited with being father to most forms of wu shu that
  stemmed from the fukien & henen shaolin temples)
the dagda (immortal s/gods from irish mythology)
prince yamato take (japanese folktale)
jason aeson (jason and the argonaugts)
perseus (sone of zeus, king of immortals. ancient greek)
siegfried (scandanavian, you know, the norns etc)
beowulf (slaying of grendel, scandanavian)
yuki-onna (well knowm japanese folktale)
uraschimataro (uraschimataro and the turtle, japanese
  folk tale. turtle takes him underwater and he lives for
  300 hundered years and comes back to land to find everyone eh
  knows dead. fits your bill?)

Not all of these are from Anime

Note: Some of these characters aren't not neccessarily immortal, but they
live for an inconcievably long time, many times the difference is not
clearly defined:
?=questionable

Anime:

Vampire Hunter D

Darkstalkers
Zambiwhatsisname: Lord Raptor
?Felicia
Maximo Dimitri
J. Tolban
Jedah (interdimentional vampire)
Morrigan
Lillith (Morrigan's "sister")
Huirzil
Dyron
?Victor  
Hsien-ko (lei lei)
Anakaris
Bishamon 
?Donovan

SFIII:

Gill (he can resurect, remember?)
?Urien
?Oro

KI:

?Cinder
Eyedol
Spinal
?Wulf

Master Mosquiton (Vampire in an obscure anime of the same name)

Slayer:
Rezo (although he was killed by like, Satan er something in the first
season)

Pai
Yakumo
Kiayan Wang
Bernares

El Hazard:
?Makoto
Ifruita

Ryoko
Washu
Kane (Tenchi in Love)
Tenchi's Granpa

Ninja High School:
Lillith (demon)
Stanly (demon)
Prof. Azland (time traveler)
Mai(tt)
Celande (tt)
Arnie
Count Bosco
Jesibel

Gold Digger:
?Gen
Proffessor Peachbody and his attack boy, Benji (Time T)

Athena (Dean Hsieh):
Athena
Dionysis
Hephaestus
Emmeleia
Apollo
Herma
Aphrodyte


South Park:
Santa Claus
Jesus
Kenny

Ogre Slayer
Ogre

Bernie (from "Weekend at Bernes II")

Tuck, Everlasting.

"The Last Unicorn" Lady Amalthea

Mermaid Saga:

Yuta
Mana
Lost Soals
Mermaids

Inu-yasha

TT:
Fire Tripper
Time Stranger

Queen Beryl and Company

?Sailor Senshi (if resurection counts)

Totoro

The Dungeon Master

Mars Goddumus (Fatal Fury Movie)

?Battle Angel

Just about any Tranformer/ Beast Wars Transformer

The highlander

Dracula

Bastard:
Dark Snieder
Anthrax

Darkseid
The Spectre
Thor
?Metallo

?The Dirty Pair (HAHA!)

For Eternity (Rod Espinosa):
Hazelle
Rizza
Michi
Kemika
Daphne

?Blade, the Immortal

Vampire Princess Miyu:
Miyu
Larva

Belldany
Urd
Skurd
4th goddess ( I forget her name)

Shimonic Princess:
Tiara, Japoro, Lena, Leon, Sara

Girls Revolution Utena:
All characters, as far as I know, especially Chu Chu!

Fushugi Yuugi:
Suzako
Seiyuu
?Taitskun

Gowkaizar:
That force that controlls Auga, I forget her name...

JoJo's Bizarre Adventure:
Dio

Ninja Scroll:
Gema

Yoma, Curse of the Undead:
The undead

Gargolys:
Puck
The three sisters
McBeth
Demona
Oberon
Tatiana
Cyote (original)
Banshi
Odin
Spider God

More when they come to me

Haze man
http://www.webspan.net/~hayesman