This year was a toss-up between Gleam and Odin. Odin won, mostly because I felt I needed to become more familiar with its libraries, and to get more practice in data-oriented programming and memory management. Also, it feels like a language that would be well suited to solving programming puzzles – I'll probably form a stronger opinion about this as I go along.
I'll have to see how far I get this year round. In the past I've only lasted a week or two before the end-of-year demands at work crowded out time for recreational programming.