Wow, I'm am not very good at superhero debuts. I only scored 30%.
On a side note, I recently was given a bin of about 200-300 comics from my grandma's attic. Unfortunately, I didn't get lucky and find an Action Comics #1 or any big debut issues  But there were some nice ones in there. Most were from the late 50s early 60s. I think the highest valued one I got was Flash #105. It's the first issue titled as just “The Flash”. The series was previously title “Showcase.” That issue also had the first appearance of Mirror Master. There was also an Iron Man #1 and a Captain America #1, which I thought was cool. And Justice League of America #2. A lot of the books aren't in that great of condition so I don't know how much they are actually worth but it was still fun going through the bin and it's cool just knowing I now own themÂ