Collecting is fun, and I like to collect books about my favorite subjects like cooking and gardening, wildlife and nature. I also like collecting American stamps mostly used ones. Otherwise I am trying to cut back on sewing and craft supplies, which used to be a collection nightmare. I also like collecting my favorite movies so I can watch them over and over.
I used to collect movies then Netflix/the Web arrived and provided content on demand. That sort of defeats the purpose of owning a bunch of movies. I have a nice sports card collection and I am also interested in stamps like you mentioned. I've been collecting beer bottle caps recently. I get a kick out of those. I also used to collect the snapple bottle caps or any type of bottle cap with trivia on the bottom of it.