I'm surprised this thread hasn't started yet, I was going to post mine today and realized this thread didn't exist.
Well, mine is Hob. XVI:50 in C Major. The first movement has contrasting, yet coherent themes suggestive of Beethoven and Schubert. The second movement is just nice, it's evocative of the better Mozart 2nd movements. The third movement is very humorous and Haydenesque, interesting in its own way. Far ahead of its time, rambling and concise.