I’ll start myself: I’ve been quite interested in Esperanto recently, and I am thinking of starting to actually learn the language. Esperanto is just really interesting to me, because of its history and size, compared to other conlangs. I don’t believe it will become the universal world language, like once was dreamed. And I do think esperanto has quite a few shortcomings when it comes to being an international auxilliary language. The reason I want to learn it is more just for that history and culture.
Oooh Lojban is super interesting! Really fun to think about places where it would make sense to use it. I imagine a political manifesto, or law-book would be a really good place.