Sorry if this has been done before, but I'm interested to hear about any others who only or primarily collect comics regarding one character, one writer, one general time period, etc. I imagine there are probably plenty who do this with the likes of Spider-Man/Superman/Batman/The X-Men, etc., but I'm sure there are others with more niche interests as well.
I personally collect comics featuring Colossus, with a secondary focus on Kitty Pryde and Magik that arose naturally since they are so strongly connected to him. He was my favorite superhero as a kid, and the main reason I got re-hooked on comics as an adult and started collecting is because I heard about a storyline involving him and Kitty in Excalibur that I wanted to read and I ended up buying that run on eBay.