well for me it would have to be TORN by Daniel Garcia not the presentation just getting it to look good took me months of practicing because of a couple of the moves.
for the people that know the trick it's the move near the beginning where you have half of the card restored and you're about to restore the next piece and also when you turn the card over at the end to show the card has been fully restored. other than those 2 parts of the trick I had the other stuff looking good by the end of my first week here's a video of his performance http://www.youtube.com/watch?v=mmMQ-hR8bVk
the points that took me the longest time to look good are at :49 and 1:05
I know that a lot of people will probably be saying that it's not a hard trick and I'm just complaining but keep in mind I just started doing magic in August of '07 so considering I've only been doing magic for a little under 1.5 years I did pretty good with that trick and I started to learn it in December of '07 and it took me a few months to make it look good and I'm so close to being able to do the advanced handling of it now that I should have it looking good in a few more days I showed it to my parents and they said that there was only 1 part of it that needs work so I'm hoping to get it looking good soon because it looks way more visual when you have the cards out in the open.
I went all through Youtube to try and find one video of anybody doing the advanced handling of TORN but absolutely nobody has posted on there of themselves doing the advanced handling either because they don't like it or because it's too hard for these people to do it or they may think it's impractical I don't really know but once I get it good looking I'll be sure and post it on Youtube and it'll probably be the first ever video of the advanced handling of TORN on Youtube.
Anyways I'm rambling now so I'd better stop typing now but I do have one question I've been seeing a lot of people have said that boomerang card of death trick is the hardest trick they've ever tried to do but being a beginner in magic I don't know where I can find that trick could somebody tell me which dvd or book I can find that under?