Good old Pen n Paper... I miss it so...
Well, here's mine:
Overview---> In my group, the DM was sadly the greatest shade Lawful Good ever to exist, making it difficult for my Sorcerer/Cleric to find any meaningful enemies. Thus, after finishing a quest against an "Evil Vampire" (although he never really showed he was evil, I wsa sent there to kill him for simply being a vampire, he just protected himself to no aveil). Anyway, I was knighted and was one of the King's Advisors. My alignment has always been more on the Chaotic Side and this character just happened to have been hiding a secret from the group since his conception, he was Chaotic Evil (bust smart enough not to get caught, so a Ring Of Undetectable Evil was hidden among my many Spell-Holding Rings.
So there I was, Requiem Malefactum, advisor to a kind king, as a Sorcerer, I was very charismatic and the King was nice enough to have three lovely daughters (after checking, two were lawful good or somesuch and one was lawful evil) of course, I seduced the lawful evil daughter quite quickly as I rolled 20 after 20 of successful charisma checks (I loved that +12 Cape, +5 inherent and original 19) I easily convinced the woman to kill her father and marry me, making me king. I obviously became a Tyrant as I conquered surrounding lands and became a powerful Lich. I Prestige Classed into the True Necromancer class (with undead leadership and epic feats that built my army) with which I lead a small war on what I eventually found out to be the Hidden Elven Capital.
Anyway, I grew more powerful when I found some messed up book that magically turned my levels in True Necromancer and in Cleric to raw fighter levels (Damned those Feats took long to sort out... 30 levels...). My DM actually told me later on that this was because I was too dangerous with my army, but he underestimated my resourcefullness, I had lost my undead army and due to my people discovering about my treachery all because of those pesky PCs (haha) my human army had left me as well, I basically had 21 or so levels of Sorcerer and 30 Fighter levels.
I retired my character for 2 in-game years, during which I say he forged his ultimate weapons. I took for all my fighter weapon specialisation feats the sword (longsword) and used the souls of a thousand Demons and Devils (Failed PC quest), Asmodeus' Mace-thing (other failed PC quest) and my Soulgems (BTW I became a Demilich after my reign on Western Faerun) to forge a weapon that was not only powerful enough to make a Balor quiver.
I named my ultimate blade the Dirge.
With this blade, I came back and killed every PC one by one, I basically spread chaos thoughout the material plane. I was sent a few of those Order monsters from the book, I was sent some Epic Leshay Hunter guy and killed them all.
Anyway, with my sword and my spells, I killed three waves of PCs and eventually retired the character by killing a Paragon (the equivalent of Demon lords but good), pissing off a god (St-Cuthbert or somesuch) killing him and telling the players my character left the plane.
I just remember him and 2 other of my characters ever owning so much:
Requiem Malefactum, Matt "Snake Eyes" Venomtongue and Skurge Lok'Trar.
Respectively; King Of Death/God Slayer, Demon Lord/Pirate Lord Snake Eyes and Grand Orc Warchief/ Chosen Shaman Of Nature.