From elementary through high school I actively collected Jigglypuff (the Pokemon). I think I've finally passed the 200+ different items mark.
I also amassed a large amount of vintage and modern My Little Pony figures, though I plan to sell some of them soon.
My most recent serious collection is Ouendan-related merchandise, specifically female Leaders. So, girls in gakuran. I have a surprising amount considering how rare we are supposed to be