My main collection is Lion King, so I'm trying to get all the Lion King pins that I really like.
I'm not much of a trader, but I noticed that you do need to have some good traders, in order to get some pins (some people don't want to sell, which is understandable, in the spirit of trading

)
Other then that, since I've joined some pin communities, and seeing releases from all over the world, I have a few side collections (very small ones), of Marie/Aristocats, Lotso, and the Dreams series from the Disney Store UK which I absolutely love!
And another cute one here and there, like the DLRP Olaf pin, etc ...