Heh, I remember that quest. The droid's gay British accent makes it even more funny.
Off the top of my head, one of my favorite quests was the Killian/Gizmo Junktown quest in Fallout. It had everything a good quest should have - multiple outcomes, significant impact on the game world, believable background, violence and plenty of humor. On the whole, Junktown has to be one of my favorite locations in any game, ever.
In addition to this, I enjoyed almost all quests in Torment. In that exquisite game even the most minor sidequests were incredibly imaginative and interesting. I wish all RPGs had such great quests.
Quests I hate include just about any sidequest in Baldur's Gate series and NWN, many quests in Arcanum and a few quests in Fallout 2. However, of all the sucky quests I ever had the displeasure of playing, the worst are without doubt in Daggerfall. I tell you, having to perform a hundred instances of hacking your way through an endless labyrinth of tunnels just to get some crappy leaf or kill a stupid harpy (only to learn that my current weapon can't damage the bitch, gah!) is an excellent way of alienating all but most masochist players. Random generated quests = teh suck.