Thanks. I've been collecting for less than a year now, so my collection is not just expanding, but evolving. Some tpb's which I really liked (like 100 Bullets v.1) are going to be given away so I can purchase the deluxe hardcovers. I also plan on completing Y - The Last Man, of course (one of my favourite stories, in and out of comic books), but I don't want to read through 5 volumes of the same story in one week, so I'm spreading those purchases out within half a year.
I decided to start collecting when I realized that I'm spending so much money on digital purchases, I may as well own the books physically. I appreciate the art way more when I see it on paper. Even with regards to this thread: I'm sure everyone here would agree that these pictures of our shelves don't do our collections justice. You have to have them right in front of you to truly appreciate them.
After I'm done with superheroes and American comics (probably in a couple of years), I may start checking out European stuff. I dabbled with Death Note and really liked the first volume, but my interest seems to be waning the further in I go. I also tried out Attack on Titan vol. 1, and thought it was just above mediocre. So, so far my trials with non-American stuff hasn't really been encouraging.