I attended Megacon 2013 here in Orlando a couple weeks ago and was attempting to add some sketches to my "Amazing Spider-man" and "Daredevil" blank variant covers. I was excited that Mark Waid would be in attendance but unfortunately had to cancel at the last minute. Overall, there were was only one Artist in attendance that I needed for my "collection". That was Steve McNiven who unfortunately was only signing his name and not sketching - so no sketch but he did sign (see bottom right hand corner).
That now brings my "Amazing Spider-man" Artist signature/sketch collection to 28 Artists. Hopefully next convention (Charlotte in June) I will be able to add more to the covers.
As I came up short on "Daredevil" and "Amazing Spider-man", I decided to start a new collection focusing on "Incredible Hulk" Artists. I used the blank variant cover from the recently released "Indestructible Hulk" #1 and started with two great sketches - one from Whilce Portacio and the other from Paul Pellitier. More to come on this one...
Lastly, George Perez was in attendance at Megacon and I realized I never had any sketches from him so I asked if he could sketch Ultron on the "Age of Ultron" #1 blank variant cover. Pretty quick sketch and it turned out nice.