[Tnair]

I'll always remember finally freeing the Crushbone male high elf slave, and he gives you a Dear John letter for a guard back in Felwithe, who I discovered was actually male. I wore what was probably their engagement ring for many levels.

Newbie Dark Elf rogue quests are also fun, at least two quests specifically for you to kill children (Gregor Nasin's daughter and also the halfling pregnant with a dark elf rogue GM baby(!))

Not as obscure but the Wakizashi of Frozen Skies quest was VERY satisfying to complete on a non-twink character of appropriate level. Having a Burning Rapier in one hand and an ice wakizashi in the other was neat.

Also Kerra Isle quests just because I like weird factions.

What's your favorite possibly-useless flavor quest?