My favorite has got to be Pillory of the Sleepless.
<spoiler=Pillory of the Sleepless: Enchantment--Aura, Guildpact, White/Black>http://askthejudgemtg.com/guildpact/pillory_of_the_sleepless.jpgWhich is worse--the sleep which never ends or that which never comes?
Of course, I also love the White Samurai Legendaries, probably because the best deck I have at the moment is a Soldier/Samurai Red/White with Green, Artifact and Enchantment options. Needless to say, I have won several games with that deck. I'll spoiler a list if anyone wants to know all of the cards.