I don't think anyone who has read the Cult of Cherry thread at all will be surprised to see me say that Cult of Cherry was absolutely my favourite collection of the year. It's simply perfect (except for the baby poop Creme Cerise).
Runners up would be the other two collections I ended up with nearly all of: beauty powder blushes and Fafi. Yes, yes, a lot of people hated the Fafi packaging because it used stickers, you've beat it to death, get over it. I really enjoyed the paint pots and blushes especially, and also find the lipsticks and glosses to be fun. I love, love, love, LOVE the BPBs. The colours and building capability made them steal a special bit of love from me.