I think there's been at least one year where I wrote the first fic for a fandom for Yuletide, although so far I've never requested for such a fandom. I hope you enjoy whatever gift(s) you end up getting.

You're right about megafandoms, although I find it hard to wade through everything to find the stuff I like — sorting by trope and kudos can only get you so far, and it often requires a level of time and effort that I don't have.