Best dev experience was coding one of my favorite board games. I started it early on in 2016, and while it isn't completely do finished (AI needs work and tweaks to the UI), it is functional for hot seat play.

I started doing it because I wanted to make a game and learn some things I didn't know, specifically I was interested in making AIs with different strategies. While I set out to learn this, I've learned so much more along the way.

I'm still really happy when I get to work on it, and having something to show people (that they can actually play!) is a great feeling.