Check out DCv1's "Bloodline" feats- I'm sure there's one for "Undead"- meaning the spontaneous arcane caster with that feat had some kind of undead critter in his family heritage...a la Blade, I guess.
Any undead with a touch ability would be nasty with a monk, OA Shaman (see Dragon #318 update) or spellcaster who focuses on touch spells or uses Arcane Strike. The Shaman adds a nice, flavorful twist on this- they have unarmed strikes, are divine casters, turn undead, and communicate with spirits (and as such, make nice "non-oriental" Voodoo priests, BTW).
Shadows make fine rogues...or eventually, Shadowdancers.
OTOH, cool...no kewl would be playing a PC with an undead type that is "Evil" who nonetheless is a good Cleric or Paladin- imagine the pure PATHOS of turning undead...and hurting yourself! That is either dedication or pure stupidity!
You could also go the "almost dead" route- be a Flesh Golem with the Living Construct template (Savage Species).
Or play a Warforged and say your PC is the equivalent to a Dalek/Robot Man/RoboCop- a living brain inside a mechanical body.
How about playing an undead creature who is composed of a swarm of vermin, like scarab beetles? Or flies?