Definitely preparation - loved arrowsinger since she came out and still do. Don't like it on melee champs, however.
As doubtofbuddha said. It used to have Paralyzed ability (permanently Paralyzed and Impervious, I think). This was kind of fun when you run it with lots of swap champions, grant auras etc. Too pricey for PvP though.
Oh ok, I was super confused because the ability is actually called Paralysis, and Paralyzed only exists as a condition. It's also not really meant to be used on normal champs, but I can see why some people would like it
Petrifying Gaze Grappling Hook Sweep Crushing Charge Scrapper/Portal Dancer Unleash and Heavy Charge as honorable mentions.